MAX253CUA-T

MAX253CUA-T Datasheet

MAX253

Part	Datasheet
MAX253CUA-T	MAX253CUA-T (pdf)

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MAX253 Transformer Driver for Isolated RS-485 Interface The MAX253 monolithic oscillator/power-driver is specifically designed to provide isolated power for an isolated RS-485 or RS-232 data interface. The device drives a center-tapped transformer primary from a 5V or 3.3V DC power supply. The secondary can be wound to provide any isolated voltage needed at power levels up to 1W. The MAX253 consists of a CMOS oscillator driving a pair of N-channel power switches. The oscillator runs at double the output frequency, driving a toggle flipflop to ensure 50% duty cycle to each of the switches. Internal delays are arranged to ensure break-beforemake action between the two switches. The SD pin puts the entire device into a low-power shutdown state, disabling both the power switches and oscillator. Isolated RS-485/RS-232 Power-Supply Transformer Driver High Noise-Immunity Communications Interface Isolated and/or High-Voltage Power Supplies Bridge Ground Differentials Medical Equipment Process Control Typical Operating Circuit Benefits and Features • Simple Power-Supply Transformer Driver Design for Isolated RS-485/RS-232 Data-Interface Applications • Single 5V or 3.3V Supply • Low-Current Shutdown Mode 0.4µA • Pin-Selectable Frequency 350kHz or 200kHz • 8-Pin DIP, SO, and Packages Take Minimal Board Space Ordering Information PART TEMP RANGE PIN-PACKAGE MAX253CPA 0°C to +70°C 8 Plastic DIP MAX253CSA 0°C to +70°C MAX253CUA 0°C to +70°C 8 µMAX MAX253C/D 0°C to +70°C Dice* MAX253EPA -40°C to +85°C 8 Plastic DIP MAX253ESA -40°C to +85°C MAX253ESA/V -40°C to +85°C MAX253MJA -55°C to +125°C 8 CERDIP** Contact factory for dice specifications. *Contact factory for availability and processing to MIL-STD-883. Devices are also available in a lead Pb -free/RoHS-compliant package. Specify lead-free by adding a + to the part number when ordering. /V Denotes an automotive qualified part. ON / OFF VIN 5V MAX253 OUTPUT 5V 200mA C3 C2 FREQUENCY SWITCH GND1 2 GND2 7 µMAX is a registered trademark of Maxim Integrated Products, Inc. MAX253 Transformer Driver for Isolated RS-485 Interface Absolute Maximum Ratings Supply Voltage VCC to +7V Control Input Voltages SD, FS .................-0.3V to VCC + 0.3V Output Switch Voltage D1, D2 Peak Output Switch Current D1, D2 ......................................1A Average Output Switch Current D1, D2 .........................200mA Continuous Power Dissipation TA = +70°C Plastic DIP derate 9.09mW/°C above +70°C .............727mW SO derate 5.88mW/°C above +70°C ..........................471mW µMAX derate 4.10mW/°C above +70°C .....................330mW CERDIP derate 8.00mW/°C above +70°C ..................640mW Operating Temperature Ranges MAX253C_ _ to +70°C MAX253E_ _ to +85°C MAX253MJA to +125°C Junction Temperatures MAX253C_ _/E_ MAX253MJA Storage Temperature Range .............................-65°C to +160°C Lead Temperature soldering, 10s .................................+300°C Soldering Temperature reflow PDIP, SO, µMAX lead Pb -free PDIP, SO, µMAX, CERDIP containing lead Pb ............+240°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics VCC = 5V ±10%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C. PARAMETER Switch On-Resistance Switch Frequency Operating Supply Current Note 1 Shutdown Supply Current Note 2 Shutdown Input Threshold Shutdown Input Leakage Current FS Input Threshold FS Input Leakage Current Start-Up Voltage CONDITIONS D1, D2 100mA FS = VCC or open VFS = 0V No load, VSD = 0V, FS low SD = VCC High Low High Low VFS = 0V FS = VCC MIN TYP Note 1 Operating supply current is the current used by the MAX253 only, not including load current. Note 2 Shutdown supply current includes output switch-leakage currents. MAX 500 300 UNITS Ω mA µA V µA pA µA pA V Maxim Integrated \| 2 MAX253 Transformer Driver for Isolated RS-485 Interface plot03 plot06 Typical Operating Characteristics Circuit of Figure 6, VIN = 5V ±10%, TA = +25°C, unless otherwise noted. OUTPUT RESISTANCE Ω FREQUENCY kHz 8/09 Deleted the MAX253EUA part number from the Ordering Information table 4/10 Added automotive qualified part number to the Ordering Information table 2/15 Added the Benefits and Features section PAGES CHANGED For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values min and max limits shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. 2015 Maxim Integrated Products, Inc. \| 18

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MAX253

Transformer Driver for Isolated RS-485 Interface

The MAX253 monolithic oscillator/power-driver is specifically designed to provide isolated power for an isolated RS-485 or RS-232 data interface. The device drives a center-tapped transformer primary from a 5V or 3.3V DC power supply. The secondary can be wound to provide any isolated voltage needed at power levels up to 1W.

The MAX253 consists of a CMOS oscillator driving a pair of N-channel power switches. The oscillator runs at double the output frequency, driving a toggle flipflop to ensure 50% duty cycle to each of the switches. Internal delays are arranged to ensure break-beforemake action between the two switches.

The SD pin puts the entire device into a low-power shutdown state, disabling both the power switches and oscillator.

Isolated RS-485/RS-232 Power-Supply Transformer Driver

High Noise-Immunity Communications Interface

Isolated and/or High-Voltage Power Supplies

Bridge Ground Differentials

Medical Equipment

Process Control

Typical Operating Circuit

Benefits and Features
• Simple Power-Supply Transformer Driver Design for

Isolated RS-485/RS-232 Data-Interface Applications
• Single 5V or 3.3V Supply
• Low-Current Shutdown Mode 0.4µA
• Pin-Selectable Frequency 350kHz or 200kHz
• 8-Pin DIP, SO, and Packages Take Minimal

Board Space
Ordering Information

PART

TEMP RANGE

PIN-PACKAGE

MAX253CPA
0°C to +70°C
8 Plastic DIP

MAX253CSA
0°C to +70°C

MAX253CUA
0°C to +70°C
8 µMAX

MAX253C/D
0°C to +70°C

Dice*

MAX253EPA
-40°C to +85°C
8 Plastic DIP

MAX253ESA
-40°C to +85°C

MAX253ESA/V
-40°C to +85°C

MAX253MJA
-55°C to +125°C
8 CERDIP**
*Contact factory for dice specifications. **Contact factory for availability and processing to MIL-STD-883. Devices are also available in a lead Pb -free/RoHS-compliant package. Specify lead-free by adding a + to the part number when ordering. /V Denotes an automotive qualified part.

ON / OFF

VIN 5V

MAX253

OUTPUT 5V 200mA

C3 C2

FREQUENCY SWITCH

GND1 2

GND2 7
µMAX is a registered trademark of Maxim Integrated Products, Inc.

MAX253

Transformer Driver for Isolated RS-485 Interface

Absolute Maximum Ratings

Supply Voltage VCC to +7V Control Input Voltages SD, FS .................-0.3V to VCC + 0.3V Output Switch Voltage D1, D2 Peak Output Switch Current D1, D2 ......................................1A Average Output Switch Current D1, D2 .........................200mA Continuous Power Dissipation TA = +70°C

Plastic DIP derate 9.09mW/°C above +70°C .............727mW SO derate 5.88mW/°C above +70°C ..........................471mW µMAX derate 4.10mW/°C above +70°C .....................330mW CERDIP derate 8.00mW/°C above +70°C ..................640mW

Operating Temperature Ranges MAX253C_ _ to +70°C MAX253E_ _ to +85°C MAX253MJA to +125°C

Junction Temperatures MAX253C_ _/E_ MAX253MJA

Storage Temperature Range .............................-65°C to +160°C Lead Temperature soldering, 10s .................................+300°C Soldering Temperature reflow

PDIP, SO, µMAX lead Pb -free PDIP, SO, µMAX, CERDIP containing lead Pb ............+240°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Electrical Characteristics

VCC = 5V ±10%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.

PARAMETER Switch On-Resistance Switch Frequency Operating Supply Current Note 1 Shutdown Supply Current Note 2 Shutdown Input Threshold Shutdown Input Leakage Current FS Input Threshold

FS Input Leakage Current Start-Up Voltage

CONDITIONS D1, D2 100mA FS = VCC or open VFS = 0V No load, VSD = 0V, FS low SD = VCC High Low

High Low VFS = 0V FS = VCC

MIN TYP

Note 1 Operating supply current is the current used by the MAX253 only, not including load current. Note 2 Shutdown supply current includes output switch-leakage currents.

MAX 500 300

UNITS Ω
mA µA V µA pA
µA pA V

Maxim Integrated | 2

MAX253

Transformer Driver for Isolated RS-485 Interface
plot03
plot06

Typical Operating Characteristics

Circuit of Figure 6, VIN = 5V ±10%, TA = +25°C, unless otherwise noted.

OUTPUT RESISTANCE Ω

FREQUENCY kHz
8/09 Deleted the MAX253EUA part number from the Ordering Information table
4/10 Added automotive qualified part number to the Ordering Information table
2/15 Added the Benefits and Features section

PAGES CHANGED
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values min and max limits shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
2015 Maxim Integrated Products, Inc. | 18

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 MAX253CUA-T Datasheet file may be downloaded here without warranties.

Datasheet ID: MAX253CUA-T 647280