ML4812CP

ML4812CP Datasheet

ML4812

Part	Datasheet
ML4812CP	ML4812CP (pdf)

Related Parts	Information
ML4812CQ	ML4812CQ
ML4812IQX	ML4812IQX
ML4812IQ	ML4812IQ

PDF Datasheet Preview
ML4812 Power Factor Controller • Precision buffered 5V reference • Current-input gain modulator reduces external components and improves noise immunity • Programmable ramp compensation circuit • 1A peak current totem-pole output drive • Overvoltage comparator helps prevent output voltage “runaway” • Wide common mode range in current sense comparators for better noise immunity • Large oscillator amplitude for better noise immunity The ML4812 is designed to optimally facilitate a peak current control boost type power factor correction system. Special care has been taken in the design of the ML4812 to increase system noise immunity. The circuit includes a precision reference, gain modulator, error overvoltage protection, ramp compensation, as well as a high current output. In addition, start-up is by an undervoltage lockout circuit with 6V hysteresis. In a typical application, the ML4812 functions as a current mode regulator. The current which is necessary to terminate the cycle is a product of the sinusoidal line voltage times the output of the error which is regulating the output DC voltage. Ramp compensation is programmable with an external resistor, to provide stable operation when the duty cycle exceeds Block Diagram Pin Shown is for DIP Version ISENSE GM OUT 2 EA OUT 3 ERROR + AMP ISINE 6 GAIN MODULATOR RAMP COMP 7 CT 16 SQ RQ SHDN 10 OUT 12 PWR GND 11 UNDER VOLTAGE LOCKOUT VREF 14 VCC 13 GND 15 CLOCK 9 ML4812 ML4812 16-Pin PDIP P16 ISENSE 1 GM OUT 2 EA OUT 3 4 OVP 5 ISINE 6 RAMP COMP 7 16 CT 15 GND 14 VREF 13 VCC 12 OUT 11 PWR GND 10 SHDN 9 CLOCK Top View PRODUCT SPECIFICATION ML4812 20-Pin PLCC Q20 GM OUT ISENSE NC CT GND EA OUT NC OVP ISINE 3 2 1 20 19 18 VREF 17 VCC 16 NC Ordering Information Part Number ML4812CP ML4812CQ Temperature Range 0°C to 70°C 0°C to 70°C PRODUCT SPECIFICATION Package Molded PDIP P16 Molded PLCC Q20 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. 5/31/01 0.0m 002 Stock#DS30004812 2001 Fairchild Semiconductor Corporation

PDF Datasheet Preview

ML4812

Power Factor Controller
• Precision buffered 5V reference
• Current-input gain modulator reduces external
components and improves noise immunity
• Programmable ramp compensation circuit
• 1A peak current totem-pole output drive
• Overvoltage comparator helps prevent output voltage
“runaway”
• Wide common mode range in current sense comparators
for better noise immunity
• Large oscillator amplitude for better noise immunity

The ML4812 is designed to optimally facilitate a peak current control boost type power factor correction system. Special care has been taken in the design of the ML4812 to increase system noise immunity. The circuit includes a precision reference, gain modulator, error overvoltage protection, ramp compensation, as well as a high current output. In addition, start-up is by an undervoltage lockout circuit with 6V hysteresis.

In a typical application, the ML4812 functions as a current mode regulator. The current which is necessary to terminate the cycle is a product of the sinusoidal line voltage times the output of the error which is regulating the output DC voltage. Ramp compensation is programmable with an external resistor, to provide stable operation when the duty cycle exceeds

Block Diagram Pin Shown is for DIP Version

ISENSE

GM OUT 2

EA OUT 3

ERROR + AMP

ISINE 6

GAIN MODULATOR

RAMP COMP 7

CT 16

SQ RQ

SHDN 10

OUT 12

PWR GND 11

UNDER VOLTAGE LOCKOUT

VREF 14

VCC 13

GND 15

CLOCK 9

ML4812

ML4812 16-Pin PDIP P16

ISENSE 1 GM OUT 2 EA OUT 3
4 OVP 5 ISINE 6 RAMP COMP 7
16 CT 15 GND 14 VREF 13 VCC 12 OUT 11 PWR GND 10 SHDN 9 CLOCK

Top View

PRODUCT SPECIFICATION

ML4812 20-Pin PLCC Q20

GM OUT ISENSE NC CT GND

EA OUT NC OVP

ISINE
3 2 1 20 19
18 VREF
17 VCC
16 NC
Ordering Information

Part Number ML4812CP ML4812CQ

Temperature Range 0°C to 70°C 0°C to 70°C

PRODUCT SPECIFICATION

Package Molded PDIP P16 Molded PLCC Q20

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.
5/31/01 0.0m 002 Stock#DS30004812 2001 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 ML4812CP Datasheet file may be downloaded here without warranties.

Datasheet ID: ML4812CP 634333