Reference

Voltage

+

-

+

-

R

S

Q

+

-

RESET

GND

CT

SENSE

High:

On

TL7700

SLVS220F

– JULY 1999 – REVISED AUGUST 2011

www.ti.com

FUNCTIONAL BLOCK DIAGRAM

A.

TERMINAL FUNCTIONS

TERMINAL

DESCRIPTION

NO.

NAME

P, PS, PW

DGK

connected internally to a 15-

μA constant-current source. There is a limit on the switching speed of

internal elements; even if CT is set to 0, response speeds remain at approximately 5 to 10

μs. If CT

is open, the device can be used as an adjustable-threshold noninverting comparator. If CT is low, the

CT

1

3

internal output-stage comparator is active, and the RESET output transistor is on. An external

voltage must not be applied to this terminal due to the internal structure of the device. Therefore,

drive the device using an open-collector transistor, FET, or 3-state buffer (in the low-level or

high-impedance state).

GND

4

5

Ground. Keep this terminal as low impedance to reduce circuit noise.

NC

3, 6, 7

2, 6, 7

No internal connection

Reset output. This terminal can be connected directly to a system that resets in the active-low state.

A pullup resistor usually is required because the output is an npn open-collector transistor. An

RESET

8

1

additional transistor should be connected when the active-high reset or higher output current is

required.

Voltage sense. This terminal has a threshold level of 500 mV. The sense voltage and hysteresis can

be set at the same time when the two voltage-dividing resistors are connected. The reference

SENSE

2

4

voltage is temperature compensated to inhibit temperature drift in the threshold voltage within the

operating temperature range.

5

8

Power supply. This terminal is used in an operating-voltage range of 1.8 V to 40 V.

2

Copyright

© 1999–2011, Texas Instruments Incorporated