Current-Mode PWM Controllers with

Programmable Switching Frequency

_______________________________________________________________________________________

7

Pin Description

PIN

NAME

FUNCTION

1

UVLO/EN

Externally Programmable Undervoltage Lockout. UVLO/EN programs the input start voltage. Connect

UVLO/EN to GND to disable the device. NDRV stops switching approximately 210µs after the UVLO/EN

voltage falls below 1.17V.

2

UFLG

Open-Drain Undervoltage Flag Output. UFLG is asserted low as soon as the UVLO/EN voltage falls below its

threshold.

3FB

Error-Amplifier Inverting Input

4

COMP

Error-Amplifier Output

5CS

Current-Sense Input. Current-sense connection for PWM regulation and cycle-by-cycle current limit.

Connect to the high side of the sense resistor. An RC filter may be necessary to eliminate leading-edge

spikes. Current-limit trip voltage is 1V.

6RT

Oscillator Timing Resistor Input. An RC network may be required to reduce jitter (see the Typical Application

Circuit).

7

GND

Ground Connection

8

NDRV

External n-Channel MOSFET Gate Connection

to GND.

10

IN

IN Supply. Decouple with a 10nF or larger capacitor to GND. For bootstrapped operation (MAX15000),

connect a startup resistor from the input supply line to IN. Connect the bias winding supply to IN also (see

the Typical Operating Circuit). For the MAX15001, connect IN directly to the 9.5V to 24V supply.

NDRV HIGH OUTPUT IMPEDANCE

vs. TEMPERATURE

TEMPERATURE (

°C)

60

35

10

-15

3.4

3.8

4.2

4.6

5.0

3.0

-40

85

SOURCING 20mA

ERROR AMPLIFIER OPEN-LOOP GAIN

AND PHASE vs. FREQUENCY

FREQUENCY (Hz)

100

-60

80

60

40

20

0

-20

-40

120

-200

80

40

0

-40

-80

-120

-160

1

0.1

10 100

1k

10k 100k 1M 10M 100M

MAX15000 toc22

GAIN

PHASE

Typical Operating Characteristics (continued)