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Typical operating characteristics (continued), Pin descriptions – Rainbow Electronics MAX5071 User Manual

Page 9

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MAX5070/MAX5071

High-Performance, Single-Ended, Current-Mode

PWM Controllers

_______________________________________________________________________________________

9

OUT SOURCE AND SINK CURRENTS

MAX5070 toc20

V

CC

= 15V

I

OUT

2A/div

V

OUT

10V/div

20Ons/div

C

OUT

= 10nF

2

4

3

5

8

9

7

6

10

20

220 320 420 520

120

620 720 820 920 1020

SUPPLY CURRENT (I

CC

)

vs. OSCILLATOR FREQUENCY (C

T

= 100pF)

MAX5070 toc21

FREQUENCY (kHz)

SUPPLY CURRENT (mA)

T

A

= +125°C

T

A

= +85°C

T

A

= +25°C

T

A

= -40°C

MAX5070A/MAX5071A

MAXIMUM DUTY CYCLE vs. R

T

MAX5070 toc22

R

T

(Ω)

DUTY CYCLE (%)

10k

1k

30

40

50

60

70

80

90

100

20

100

100k

C

T

= 1nF

C

T

= 560pF

C

T

= 220pF

C

T

= 100pF

Typical Operating Characteristics (continued)

(V

CC

= 15V, T

A

= +25°C, unless otherwise noted.)

Pin Descriptions

PIN

NAME

FUNCTION

1

COMP

Error-Amplifier Output. COMP can be used for soft-start.

2

FB

Error-Amplifier Inverting Input

3

CS

Input to the PWM Comparator and Overcurrent Protection Comparator. The current-sense signal is
compared to a signal proportional to the error-amplifier output voltage.

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

GND

Power-Supply Ground. Place the V

CC

and VREF bypass capacitors close to the IC to minimize

ground loops.

6

OUT

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

7

V

CC

Power-Supply Input for MAX5070. 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

VREF

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.

MAX5070A/MAX5070B