Detailed Description

The MAX5094_/MAX5095_ current-mode PWM con-

trollers are designed for use as the control and regulation

core of flyback or forward topology switching power sup-

plies. These devices incorporate an integrated low-side

driver, adjustable oscillator, error amplifier (MAX5094_

only), current-sense amplifier, 5V reference, and external

synchronization capability (MAX5095A/MAX5095B only).

overvoltage during startup.

Eight different versions of the MAX5094/MAX5095 are

available as shown in the Selector Guide. The

MAX5094A/MAX5094B are the standard versions with a

feedback input (FB) and internal error amplifier. The

MAX5095A/MAX5095B include bidirectional synchroniza-

tion (SYNC). This enables multiple MAX5095A/

MAX5095Bs to be connected and synchronized to the

device with the highest frequency. The MAX5095C

includes an ADV_CLK output, which precedes the

MAX5095C’s drive output (OUT) by 110ns. Figures 1, 2,

and 3 show the internal functional diagrams of the

MAX5094_, MAX5095A/MAX5095B, and MAX5095C,

respectively. The MAX5094A/MAX5094C/MAX5095A are

capable of 100% maximum duty cycle. The MAX5094B/

MAX5094D/MAX5095B/MAX5095C limit the maximum

duty cycle to 50%.

High-Performance, Single-Ended, Current-Mode

PWM Controllers

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11

UVLO

REFERENCE

2.5V

PREREGULATOR

5V

VOLTAGE-

DIVIDER

THERMAL

SHUTDOWN

EN-REF

BG

SNS

5V REGULATOR

VOLTAGE-

DIVIDER

8

7

26.5V

REF

2.5V

VP

REG_OK

DELAY

S

R

Q

OSC

Q

6 OUT

ILIM

CPWM

1V (MAX5094A/B)

0.3V (MAX5094C/D)

EN-DRV-BAR

R

2R

VEA

3

5

2

1

CS

GND

FB

COMP

CLK

MAX5094_

VP

2.5V

8.4V/7.6V

100% MAX DUTY CYCLE (MAX5094A/MAX5094C)

50% MAX DUTY CYCLE (MAX5094B/MAX5094D)

Figure 1. MAX5094_ Functional Diagram