TL7702B, TL7705B
SUPPLY-VOLTAGE SUPERVISORS
SLVS037H – SEPTEMBER 1989 – REVISED JULY 1999
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
Power-On Reset Generator
Automatic Reset Generation After
Voltage Drop
RESET Output Defined From V
CC
≥
1 V
Precision Voltage Sensor
Temperature-Compensated Voltage
Reference
True and Complement Reset Outputs
Externally Adjustable Pulse Duration
description
The TL7702B and TL7705B are integrated-circuit
supply-voltage supervisors designed for use as
reset
controllers
in
microprocessor systems. The supply-voltage
supervisor monitors the supply for undervoltage
conditions at the SENSE input. During power up,
the RESET output becomes active (low) when
V
CC
attains a value approaching 1 V. As V
CC
approaches 3 V (assuming that SENSE is above
V
T+
), the delay timer function activates a time
delay, after which outputs RESET and RESET go
inactive (high and low, respectively). When an
undervoltage condition occurs during normal
operation, outputs RESET and RESET go active.
To ensure that a complete reset occurs, the reset
outputs remain active for a time delay after the
voltage at the SENSE input exceeds the
positive-going threshold value. The time delay is
determined by the value of the external capacitor
C
T
: t
d
≈
2.6
×
10
4
×
C
T
, where C
T
is in farads (F)
and t
d
is in seconds (s).
An external capacitor (typically 0.1
μ
F) must be
connected to REF to reduce the influence of fast
transients in the supply voltage.
microcomputer
and
The TL7702BC and TL7705BC are characterized for operation from 0
°
C to 70
°
C. The TL7702BI and TL7705BI
are characterized for operation from –40
°
C to 85
°
C. The TL7705BQ is characterized for operation from –40
°
C
to 125
°
C. The TL7705BM is characterized for operation from –55
°
C to 125
°
C.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright
1999, Texas Instruments Incorporated
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
3
2 1 20 19
9 10 11 12 13
4
5
6
7
8
18
17
16
15
14
NC
SENSE
NC
RESET
NC
NC
RESIN
NC
CT
NC
TL7705BM . . . FK PACKAGE
(TOP VIEW)
N
R
N
R
N
V
N
N
G
N
C
1
2
3
4
8
7
6
5
REF
RESIN
CT
GND
V
CC
SENSE
RESET
RESET
TL77xxBC . . . D OR P PACKAGE
TL7705BM . . . JG PACKAGE
TL7705BQ . . . D PACKAGE
(TOP VIEW)
1
2
3
4
5
10
9
8
7
6
NC
REF
RESIN
CT
GND
NC
V
CC
SENSE
RESET
RESET
TL7705BM . . . U PACKAGE
(TOP VIEW)
NC – No internal connection
NC – No internal connection