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Pin descriptions (continued) – Rainbow Electronics MAX5071 User Manual

Page 10

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MAX5070/MAX5071

High-Performance, Single-Ended, Current-Mode
PWM Controllers

10

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Pin Descriptions (continued)

PIN

MAX5071A/

MAX5071B

MAX5071C

NAME

FUNCTION

1

1

COMP

COMP is level-shifted and connected to the inverting input of the PWM comparator. Pull
up COMP to VREF through a resistor and connect an optocoupler from COMP to GND for
proper operation.

2

SYNC

Bidirectional Synchronization Input. When synchronizing with other
MAX5071A/MAX5071Bs, the higher frequency part synchronizes all other devices.

2

ADV_CLK

ADV_CLK is an 85ns clock output pulse preceding the rising edge of OUT (see Figure 4).
Use the pulse to drive the secondary-side synchronous rectifiers through a pulse
transformer or an optocoupler (see Figure 8).

3

3

CS

Input to the PWM Comparator and Overcurrent Protection Comparator. The current-
sense signal is compared to the voltage at COMP.

4

4

R

T

/C

T

Timing Resistor and Capacitor Connection. A resistor R

T

from R

T

/C

T

to VREF and

capacitor C

T

from R

T

/C

T

to GND set the oscillator frequency.

5

5

GND

Power-Supply Ground. Place the V

CC

and VREF bypass capacitors close to the IC to

minimize ground loops.

6

6

OUT

MOSFET Driver Output. OUT connects to the gate of the external n-channel MOSFET.

7

7

V

CC

Power-Supply Input for MAX5071. Bypass V

CC

to GND with a 0.1µF ceramic capacitor or

a parallel combination of a 0.1µF and a higher value ceramic capacitor.

8

8

V

REF

5V Reference Output. Bypass VREF to GND with a 0.1µF ceramic capacitor or a parallel
combination of a 0.1µF and a higher value ceramic capacitor.

MAX5071A/MAX5071B/MAX5071C