FAN2535S26X

FAN2535S26X Datasheet

FAN2534/FAN2535

Part	Datasheet
FAN2535S26X	FAN2535S26X (pdf)

Related Parts	Information
FAN2535S285X	FAN2535S285X

PDF Datasheet Preview
FAN2534/FAN2535 150 mA CMOS LDO Regulator with Fast Start, Enable • 70dB Ripple rejection >45dB up to 1MHz • 150µsec Power On Time • 150µsec Enable Time • Low noise - 50µVrms • Enable optimized for CDMA time slices • 180 mV dropout voltage at 150 mA • Enable/Shutdown Control • Enable time independent of noise bypass capacitor value • SOT23-5 package • Thermal limiting • 300 mA trimmed current limit • Cellular Phones and accessories • PDAs • Portable cameras and video recorders • Laptop, notebook and palmtop computers The FAN2534/FAN2535 family of micropower low-dropout voltage regulators utilize CMOS technology to offer a new level of cost-effective performance in GSM, TDMA, and CDMA cellular handsets, laptop and notebook computers, and other portable devices. Proprietary design technics ensure high ripple rejection. Other features include low noise, short circuit current limit, thermal shutdown circuit, low dropout voltage, fast enable required in CDMA handset applications, exceptional loop stability to accommodate a wide variety of external capacitors, and a compact SOT23-5 surface-mount package. These products offer improvements over older Bipolar and CMOS designs and are pin-compatible with many popular devices. The FAN2534 and FAN2535 devices are distinguished by the assignment of pin 4: FAN2534 pin 4 ADJ, allowing the user to adjust the output voltage over a wide range using an external voltage divider. FAN2534-XX pin 4 BYP, to which a bypass capacitor may be connected for optimal noise performance. Output voltage is as by the XX. FAN2535-XX pin 4 ERR, a which indicates that the output voltage has dropped below the minimum due to a fault condition. The standard output voltages available are 2.6V, 2.85V, and 3.0V Custom output voltages are also available please contact your local Fairchild Sales for information. Block Diagrams VIN Bandgap FAN2534 Error Amplifier VOUT Thermal Sense ADJ GND VIN Bandgap Error Amplifier Thermal Sense FAN2534-XX VIN Bandgap VOUT Error Amplifier ERR VOUT Thermal Sense FAN2535-XX FAN2534/FAN2535 Pin Assignments PRODUCT SPECIFICATION VIN 1 FB SHDN GND 2 CAP+ EN 3 CAP- 5 VOUT 4 ADJ/BYP/ERR Pin No. FAN2534 VIN GND EN ADJ VOUT FAN2534-XX VIN GND EN BYP VOUT For specific output voltages of the fixed oputput voltage versions please refer to the table "Output Voltage Options and Ordering Information" on Page Custom fixed output voltages, not listed in the table, are also available. Unless otherwise stated, TA = 25°C, VIN = VOUT + 1V, IOUT = 100µA, VEH > V. Bold values indicate -40 <TJ <125°C. Dropout Voltage is defined as the input to output differential at which the output voltage drops to 2% below the nominal value measured at 1V input - output differential. Adjustable version, has a bandgap reference voltage of 1.0V, trimmed to +/-1% initial accuracy. When using repeated cycling, F>0.5Hz. PRODUCT SPECIFICATION FAN2534/FAN2535 Functional Description Utilizing CMOS technology, the FAN2534/FAN2535 product family is optimized for use in compact battery powered systems, offering a unique combination of high ripple rejection, low noise, low power consumption, extremely low dropout voltages, high tolerance for a variety of output capacitors, and less than 1µA "OFF" current. In the circuit, a differential controls a series-pass P-Channel MOSFET, and a separate error compares the load voltage at the output with an onboard trimmed low voltage bandgap reference. The series resistance of the pass P-Channel MOSFET is approximately 1 Ohm, yielding an unusually low dropout voltage even under high load conditions. Thermal shutdown and current limit circuits protect the device under extreme conditions. When the device temperature reaches 155°C, the output is disabled, until the device cooles down by 15°C, then re-enabled. The user can to shut down the device using the Enable control pin at any time. The current limit circuit is trimmed, which leads to consistent power on /enable delays, and provides safe short circuit current densities even in narrow traces of the PCB. A carefully optimized control loop accommodates a wide range of ESR values in the output bypass capacitor, allowing the user to optimize space, cost, and performance requirements. An Enable pin shuts down the regulator output to conserve power, reducing supply current to less than 1µA. The output can then be re-Enabled within 150µSec, the fast power-cycling needs of CDMA applications. Depending on the device type selected, other control and status functions are available at pin The versions are available with either a noise-bypass pin or an Error pin option. The error can be used as a diagnostic function to indicate that the output voltage has dropped more than 5% below the nominal value. The adjustable-voltage versions utilize pin 4 to connect to an external voltage divider which feeds back to the regulator error thus setting the output voltage to the desired value. Applications Information External Capacitors Selection The FAN2534/FAN2535 allows the user to utilize a wide variety of capacitors compared to other LDO products. An innovative design approach offers reduced sensitivity to ESR Equivalent Series Resistance , which degrades regulator loop stability in older designs. While the improvements featured in the FAN2534/FAN2535 family greatly simplify the design task, capacitor quality still must be considered if the designer is to achieve optimal circuit performance. In general, ceramic capacitors offer superior ESR performance, and a smaller case size than tantalums. Input Capacitor An input capacitor of 2.2µF nominal value or greater, connected between the Input pin and Ground, placed in close proximity to the device, will improve transient response and ripple rejection. Higher values will further improve ripple rejection and transient response. An input capacitor is recommended when the input source, either a battery or a regulated AC voltage, is located far from the device. Any good quality ceramic, tantalum, or metal capacitor will give acceptable performance, however in extreme cases capacitor surge current ratings may have to be considered. Output Capacitor An output capacitor is required to maintain regulator loop stability. Stable operation will be achieved with a wide variety of capacitors with ESR values ranging from up to Multilayer ceramic, tantalum or aluminum electrolytic capacitors may be used. A nominal value of at least 1µF is recommended. Note that the choice of output capacitor effects load transient response, ripple rejection, and it has a slight effect on noise performance as well. Bypass Capacitor FAN2534-XX Only In the connecting a capacitor between the bypass pin and ground can reduce output noise. Values ranging from 0pF to 47nF can be used, depending on the sensitivity to output noise in the application. At the high-impedance Bypass pin, care must be taken in the PCB layout to minimize noise pickup, and capacitors must be selected to minimize current loading leakage . Noise pickup from external sources can be considerable. Leakage currents into the Bypass pin will directly affect regulator accuracy and should be kept as low as possible thus, highquality ceramic and types are recommended for their low leakage characteristics. Cost-sensitive applications not concerned with noise can omit this capacitor. FAN2534/FAN2535 PRODUCT SPECIFICATION Control Functions Enable Pin Connecting 2.0V or greater to the Enable pin will enable the output, while 0.4V or less will disable it while reducing the quiescent current consumption to less than 1µA. If this shutdown function is not needed, the pin can simply be connected permanently to the VIN pin. Allowing this pin to will cause erratic operation. Error Flag FAN2535-XX Only Fault conditions such as input voltage dropout low VIN , overheating, or overloading excessive output current , will set an error The ERR pin which is an open-drain output, will go LOW when VOUT is less than 95% or the output voltage. When the voltage at VOUT is greater than 95% of the output voltage, the ERR pin is HIGH. A logic pullup resistor of 100K Ohm is recommended at this output. The pin can be left disconnected if unused. Thermal Protection The FAN2534/FAN2535 is designed to supply high peak output currents for brief periods, however sustained excessive output load at high input - output voltage difference will cause the device temperature to increase and exceed maximum ratings due to power dissipation. During output overload conditions, when the die temperature exceeds the shutdown limit temperature of 155°C, an onboard thermal protection will disable the output until the temperature drops approximately 15°C below the limit, at which point the output is re-enabled. During a thermal shutdown situation the user may assert the power-down function at the Enable pin, reducing power consumption to a minimum. Thermal Characteristics The FAN2534/FAN2535 is designed to supply 150mA at the output voltage with an operating die junction temperature of up to 125°C. Once the power dissipation and thermal resistance is known, the maximum junction temperature of the device can be calculated. While the power dissipation is calculated from known electrical parameters, the actual thermal resistance depends on the thermal characteristics of the SOT23-5 surface-mount package and the surrounding PC Board copper to which it is mounted. The power dissipation is equal to the product of the input-tooutput voltage differential and the output current plus the ground current multiplied by the input voltage, or: PD = VIN VOUT IOUT + VINIGND The relationship describing the thermal behavior of the package is: PD max where TJ max is the maximum allowable junction temperature of the die, which is 125°C, and TA is the ambient operating temperature. is dependent on the surrounding PC board layout and can be empirically obtained. While the junction-to-case of the SOT23-5 package is at 130°C /W, the of the minimum PWB footprint will be at least 235°C /W. This can be improved upon by providing a heat sink of surrounding copper ground on the PWB. Depending on the size of the copper area, the resulting can range from approximately 180°C /W for one square inch to nearly 130°C /W for 4 square inches. The addition of backside copper with through-holes, stiffeners, and other enhancements can also aid in reducing thermal resistance. Output Voltage Options and Ordering Information Product Number FAN2534SX FAN2534S26X FAN2534S30X FAN2535S26X FAN2535S285X VOUT Adj. Pin 4 Function Adjust Bypass Error output Error output Tape and Reel Information Quantity 3000 Reel Size 7" Width 8mm FAN2534/FAN2535 Package Marking AJA AJG AJW AKG AKN DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: Life support devices or systems are devices or systems which, a are intended for surgical implant into the body, or b support or sustain life, and c whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 8/26/03 0.0m 004 Stock#DS30002591 2002 Fairchild Semiconductor Corporation

PDF Datasheet Preview

FAN2534/FAN2535
150 mA CMOS LDO Regulator with Fast Start, Enable
• 70dB Ripple rejection >45dB up to 1MHz
• 150µsec Power On Time
• 150µsec Enable Time
• Low noise - 50µVrms
• Enable optimized for CDMA time slices
• 180 mV dropout voltage at 150 mA
• Enable/Shutdown Control
• Enable time independent of noise bypass capacitor value
• SOT23-5 package
• Thermal limiting
• 300 mA trimmed current limit
• Cellular Phones and accessories
• PDAs
• Portable cameras and video recorders
• Laptop, notebook and palmtop computers

The FAN2534/FAN2535 family of micropower low-dropout voltage regulators utilize CMOS technology to offer a new level of cost-effective performance in GSM, TDMA, and CDMA cellular handsets, laptop and notebook computers, and other portable devices. Proprietary design technics ensure high ripple rejection. Other features include low noise, short circuit current limit, thermal shutdown circuit,
low dropout voltage, fast enable required in CDMA handset applications, exceptional loop stability to accommodate a wide variety of external capacitors, and a compact SOT23-5 surface-mount package. These products offer improvements over older Bipolar and CMOS designs and are pin-compatible with many popular devices.

The FAN2534 and FAN2535 devices are distinguished by the assignment of pin 4:

FAN2534 pin 4 ADJ, allowing the user to adjust the output voltage over a wide range using an external voltage divider.

FAN2534-XX pin 4 BYP, to which a bypass capacitor may be connected for optimal noise performance. Output voltage is as by the XX.

FAN2535-XX pin 4 ERR, a which indicates that the output voltage has dropped below the minimum due to a fault condition.

The standard output voltages available are 2.6V, 2.85V, and 3.0V Custom output voltages are also available please contact your local Fairchild Sales for information.

Block Diagrams

VIN Bandgap

FAN2534

Error

Amplifier

VOUT

Thermal Sense

ADJ GND

VIN Bandgap

Error

Amplifier

Thermal Sense

FAN2534-XX

VIN Bandgap

VOUT

Error

Amplifier

ERR VOUT

Thermal Sense

FAN2535-XX

FAN2534/FAN2535

Pin Assignments

PRODUCT SPECIFICATION

VIN 1 FB SHDN

GND 2 CAP+

EN 3 CAP-
5 VOUT 4 ADJ/BYP/ERR

Pin No.

FAN2534 VIN GND EN ADJ VOUT

FAN2534-XX VIN GND EN BYP VOUT
For specific output voltages of the fixed oputput voltage versions please refer to the table "Output Voltage Options and Ordering Information" on Page Custom fixed output voltages, not listed in the table, are also available.

Unless otherwise stated, TA = 25°C, VIN = VOUT + 1V, IOUT = 100µA, VEH > V. Bold values indicate -40 <TJ <125°C. Dropout Voltage is defined as the input to output differential at which the output voltage drops to 2% below the nominal value
measured at 1V input - output differential.

Adjustable version, has a bandgap reference voltage of 1.0V, trimmed to +/-1% initial accuracy.

When using repeated cycling, F>0.5Hz.

PRODUCT SPECIFICATION

FAN2534/FAN2535

Functional Description

Utilizing CMOS technology, the FAN2534/FAN2535 product family is optimized for use in compact battery powered systems, offering a unique combination of high ripple rejection, low noise, low power consumption, extremely low dropout voltages, high tolerance for a variety of output capacitors, and less than 1µA "OFF" current. In the circuit, a differential controls a series-pass P-Channel MOSFET, and a separate error compares the load voltage at the output with an onboard trimmed low voltage bandgap reference. The series resistance of the pass P-Channel MOSFET is approximately 1 Ohm, yielding an unusually low dropout voltage even under high load conditions.

Thermal shutdown and current limit circuits protect the device under extreme conditions. When the device temperature reaches 155°C, the output is disabled, until the device cooles down by 15°C, then re-enabled. The user can to shut down the device using the Enable control pin at any time. The current limit circuit is trimmed, which leads to consistent power on /enable delays, and provides safe short circuit current densities even in narrow traces of the PCB.

A carefully optimized control loop accommodates a wide range of ESR values in the output bypass capacitor, allowing the user to optimize space, cost, and performance requirements.

An Enable pin shuts down the regulator output to conserve power, reducing supply current to less than 1µA. The output can then be re-Enabled within 150µSec, the fast power-cycling needs of CDMA applications.

Depending on the device type selected, other control and status functions are available at pin The versions are available with either a noise-bypass pin or an Error pin option. The error can be used as a diagnostic function to indicate that the output voltage has dropped more than 5% below the nominal value.

The adjustable-voltage versions utilize pin 4 to connect to an external voltage divider which feeds back to the regulator error thus setting the output voltage to the desired value.

Applications Information

External Capacitors Selection

The FAN2534/FAN2535 allows the user to utilize a wide variety of capacitors compared to other LDO products. An innovative design approach offers reduced sensitivity to ESR Equivalent Series Resistance , which degrades regulator loop stability in older designs. While the improvements featured in the FAN2534/FAN2535 family greatly simplify the design task, capacitor quality still must be considered if the designer is to achieve optimal circuit performance. In general, ceramic capacitors offer superior ESR performance, and a smaller case size than tantalums.

Input Capacitor

An input capacitor of 2.2µF nominal value or greater, connected between the Input pin and Ground, placed in close proximity to the device, will improve transient response and ripple rejection. Higher values will further improve ripple rejection and transient response. An input capacitor is recommended when the input source, either a battery or a regulated AC voltage, is located far from the device. Any good quality ceramic, tantalum, or metal capacitor will give acceptable performance, however in extreme cases capacitor surge current ratings may have to be considered.

Output Capacitor

An output capacitor is required to maintain regulator loop stability. Stable operation will be achieved with a wide variety of capacitors with ESR values ranging from up to Multilayer ceramic, tantalum or aluminum electrolytic capacitors may be used. A nominal value of at least 1µF is recommended. Note that the choice of output capacitor effects load transient response, ripple rejection, and it has a slight effect on noise performance as well.

Bypass Capacitor FAN2534-XX Only

In the connecting a capacitor between the bypass pin and ground can reduce output noise. Values ranging from 0pF to 47nF can be used, depending on the sensitivity to output noise in the application.

At the high-impedance Bypass pin, care must be taken in the PCB layout to minimize noise pickup, and capacitors must be selected to minimize current loading leakage . Noise pickup from external sources can be considerable. Leakage currents into the Bypass pin will directly affect regulator accuracy and should be kept as low as possible thus, highquality ceramic and types are recommended for their low leakage characteristics. Cost-sensitive applications not concerned with noise can omit this capacitor.

FAN2534/FAN2535

PRODUCT SPECIFICATION

Control Functions

Enable Pin Connecting 2.0V or greater to the Enable pin will enable the output, while 0.4V or less will disable it while reducing the quiescent current consumption to less than 1µA. If this shutdown function is not needed, the pin can simply be connected permanently to the VIN pin. Allowing this pin to will cause erratic operation.

Error Flag FAN2535-XX Only Fault conditions such as input voltage dropout low VIN , overheating, or overloading excessive output current , will set an error The ERR pin which is an open-drain output, will go LOW when VOUT is less than 95% or the output voltage. When the voltage at VOUT is greater than 95% of the output voltage, the ERR pin is HIGH. A logic pullup resistor of 100K Ohm is recommended at this output. The pin can be left disconnected if unused.

Thermal Protection The FAN2534/FAN2535 is designed to supply high peak output currents for brief periods, however sustained excessive output load at high input - output voltage difference will cause the device temperature to increase and exceed maximum ratings due to power dissipation. During output overload conditions, when the die temperature exceeds the shutdown limit temperature of 155°C, an onboard thermal protection will disable the output until the temperature drops approximately 15°C below the limit, at which point the output is re-enabled. During a thermal shutdown situation the user may assert the power-down function at the Enable pin, reducing power consumption to a minimum.

Thermal Characteristics

The FAN2534/FAN2535 is designed to supply 150mA at the output voltage with an operating die junction temperature of up to 125°C. Once the power dissipation and thermal resistance is known, the maximum junction temperature of the device can be calculated. While the power dissipation is calculated from known electrical parameters, the actual thermal resistance depends on the thermal characteristics of the SOT23-5 surface-mount package and the surrounding PC Board copper to which it is mounted.

The power dissipation is equal to the product of the input-tooutput voltage differential and the output current plus the ground current multiplied by the input voltage, or:

PD = VIN VOUT IOUT + VINIGND

The relationship describing the thermal behavior of the package is:

PD max
where TJ max is the maximum allowable junction temperature of the die, which is 125°C, and TA is the ambient operating temperature. is dependent on the surrounding PC board layout and can be empirically obtained. While the junction-to-case of the SOT23-5 package is at 130°C /W, the of the minimum PWB footprint will be at least 235°C /W. This can be improved upon by providing a
heat sink of surrounding copper ground on the PWB. Depending on the size of the copper area, the resulting can range from approximately 180°C /W for one square inch
to nearly 130°C /W for 4 square inches. The addition of
backside copper with through-holes, stiffeners, and other
enhancements can also aid in reducing thermal resistance.
Output Voltage Options and Ordering Information

Product Number FAN2534SX FAN2534S26X FAN2534S30X FAN2535S26X FAN2535S285X

VOUT Adj.

Pin 4 Function Adjust Bypass

Error output Error output

Tape and Reel Information

Quantity 3000

Reel Size 7"

Width 8mm

FAN2534/FAN2535

Package Marking AJA AJG AJW AKG AKN

DISCLAIMER

FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.

LIFE SUPPORT POLICY

FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein:

Life support devices or systems are devices or systems which, a are intended for surgical implant into the body, or b support or sustain life, and c whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user.

A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.
8/26/03 0.0m 004 Stock#DS30002591 2002 Fairchild Semiconductor Corporation

Notice: we do not provide any warranties that information, datasheets, application notes, circuit diagrams, or software stored on this website are up-to-date or error free. The archived FAN2535S26X Datasheet file may be downloaded here without warranties.

Datasheet ID: FAN2535S26X 513886