ML4826CP2

ML4826CP2 Datasheet

ML4826

Part	Datasheet
ML4826CP2	ML4826CP2 (pdf)

PDF Datasheet Preview
ML4826 PFC and Dual Output PWM Controller Combo • Internally synchronized PFC and PWM in one IC • Low total harmonic distortion • Low ripple current in the storage capacitor between the PFC and PWM sections • Average current, continuous boost, leading edge PFC • High trailing edge PWM with dual totem-pole outputs • Average line voltage compensation with brown-out control • PFC overvoltage comparator eliminates output “runaway” due to load removal • Current-fed multiplier for improved noise immunity • Overvoltage protection, UVLO, and soft start The ML4826 is a high power controller for power factor corrected, switched mode power supplies. PFC allows the use of smaller, lower cost bulk capacitors, reduces power line loading and stress on the switching FETs, and results in a power supply that fully complies with IEC1000-3-2 The ML4826 includes circuits for the implementation of a leading edge, average current “boost” type power factor correction and a trailing edge, pulse width modulator PWM with dual totem-pole outputs. An over-voltage comparator shuts down the PFC section in the event of a sudden decrease in load. The PFC section also includes peak current limiting and input voltage brown-out protection. The PWM section can be operated in current or voltage mode at up to 250kHz and includes a duty cycle limit to prevent transformer saturation. Block Diagram 20 11 VEAO AGND 1 IEAO VFB 19 2.5V IAC 2 VRMS 4 ISENSE 3 VEA - IEA - GAIN MODULATOR POWER FACTOR CORRECTOR OVP + 2.7V + -1V + - PFC ILIMIT VCCZ 13.5V 17 VCC 7.5V REFERENCE VREF 18 RQ SQ PFC OUT 15 RAMP 1 8 RTCT 7 OSCILLATOR VCC2 RAMP 2 9 VDC 6 50µA DC ILIMIT 10 1.5V DUTY CYCLE LIMIT VIN OK Ordering Information Part Number ML4826CP2 PWM Frequency 2 x PFC Temperature Range 0°C to 70°C PRODUCT SPECIFICATION Package 20-Pin PDIP 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. 2/14/02 0.0m 003 Stock#DS30004826 2001 Fairchild Semiconductor Corporation

PDF Datasheet Preview

ML4826

PFC and Dual Output PWM Controller Combo
• Internally synchronized PFC and PWM in one IC
• Low total harmonic distortion
• Low ripple current in the storage capacitor between the

PFC and PWM sections
• Average current, continuous boost, leading edge PFC
• High trailing edge PWM with dual totem-pole
outputs
• Average line voltage compensation with brown-out
control
• PFC overvoltage comparator eliminates output “runaway”
due to load removal
• Current-fed multiplier for improved noise immunity
• Overvoltage protection, UVLO, and soft start

The ML4826 is a high power controller for power factor corrected, switched mode power supplies. PFC allows the use of smaller, lower cost bulk capacitors, reduces power line loading and stress on the switching FETs, and results in a power supply that fully complies with IEC1000-3-2 The ML4826 includes circuits for the implementation of a leading edge, average current “boost” type power factor correction and a trailing edge, pulse width modulator PWM with dual totem-pole outputs.

An over-voltage comparator shuts down the PFC section in the event of a sudden decrease in load. The PFC section also includes peak current limiting and input voltage brown-out protection. The PWM section can be operated in current or voltage mode at up to 250kHz and includes a duty cycle limit to prevent transformer saturation.

Block Diagram
20 11

VEAO

AGND
1 IEAO

VFB 19
2.5V IAC 2

VRMS 4

ISENSE 3

VEA -

IEA -

GAIN MODULATOR

POWER FACTOR CORRECTOR

OVP + 2.7V + -1V + -

PFC ILIMIT

VCCZ 13.5V
17 VCC
7.5V REFERENCE

VREF 18

RQ SQ

PFC OUT 15

RAMP 1 8

RTCT 7

OSCILLATOR

VCC2

RAMP 2 9

VDC 6
50µA

DC ILIMIT 10
1.5V

DUTY CYCLE LIMIT

VIN OK
Ordering Information

Part Number ML4826CP2

PWM Frequency 2 x PFC

Temperature Range 0°C to 70°C

PRODUCT SPECIFICATION

Package 20-Pin PDIP

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.
2/14/02 0.0m 003 Stock#DS30004826 2001 Fairchild Semiconductor Corporation

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Datasheet ID: ML4826CP2 634335