TI TL7700CPW

TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
D
D
D
D
D
D
D
P, PS, OR PW PACKAGE
(TOP VIEW)
Adjustable Sense Voltage With Two
External Resistors
Adjustable Hysteresis of Sense Voltage
Wide Operating Supply-Voltage
Range . . . 1.8 V to 40 V
Wide Operating-Temperature
Range . . . –40°C to 85°C
Low Power Consumption (ICC = 0.6 mA
TYP, VCC = 40 V)
Minimum External Components
Package Options Include Plastic
Small-Outline (PS) and Thin Shrink
Small-Outline (PW) Packages and Standard
DIP (P)
CT
SENSE
NC
GND
1
8
2
7
3
6
4
5
RESET
NC
NC
VCC
NC – No internal connection
description
The TL7700 is a bipolar integrated circuit designed for use as a reset controller in microcomputer and
microprocessor systems. The SENSE voltage can be set to any value greater than 0.5 V using two external
resistors. The hysteresis value of the sense voltage also can be set by the same resistors. The device includes
a precision voltage reference, fast comparator, timing generator, and output driver, so it can generate a
power-on reset signal in a digital system.
The TL7700 has an internal 1.5-V temperature-compensated voltage reference from which all function blocks
are supplied. Circuit function is very stable, with supply voltage in the 1.8-V to 40-V range. Minimum supply
current allows use with ac line operation, portable battery operation, and automotive applications.
The TL7700C is characterized for operation from –40°C to 85°C.
AVAILABLE OPTIONS
PACKAGED DEVICES
TA
–40°C to 85°C
PLASTIC
DIP
(P)
PLASTIC
SMALL OUTLINE
(PS)
PLASTIC
THIN SHRINK
SMALL OUTLINE
(PW)
TL7700CP
TL7700CPS
TL7700CPW
PS and PW packages are available taped and reeled. Add the suffix R to device type
(e.g., TL7700CPSR).
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
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.
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1
TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
functional block diagram
VCC
Vs = 500 mV TYP
RESET
Reference
Voltage
+
–
SENSE
+
+
–
–
ICT†
High:
On
R
Q
S
IS†
GND
†ICT = 15 µA TYP; Is = 2.5 µA TYP
CT
Terminal Functions
TERMINAL
NAME
CT
GND
NC
2
DESCRIPTION
NO.
1
Timing capacitor connection. This terminal sets the RESET output pulse duration (tpo). It is 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 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).
4
Ground. Keep this terminal as low impedance to reduce circuit noise.
3, 6, 7
No internal connection
RESET
8
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 additional transistor should be connected
when the active-high reset or higher output current is required.
SENSE
2
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 voltage is temperature compensated to inhibit
temperature drift in the threshold voltage within the operating temperature range.
VCC
5
Power supply. This terminal is used in an operating-voltage range of 1.8 V to 40 V.
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TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 V
Sense input voltage range, Vs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to 41 V
Output voltage, VOH (off state) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 V
Output current, IOL (on state) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 mA
Package thermal impedance, θJA (see Notes 2 and 3): P package . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85°C/W
PS package . . . . . . . . . . . . . . . . . . . . . . . . . . . 95°C/W
PW package . . . . . . . . . . . . . . . . . . . . . . . . . 149°C/W
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES: 1. All voltage values are with respect to the network ground terminal.
2. Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable
ambient temperature is PD = (TJ(max) – TA)/θJA. Operating at the absolute maximum TJ of 150°C can impact reliability.
3. The package thermal impedance is calculated in accordance with JESD 51.
recommended operating conditions
MIN
Supply voltage, VCC
NOM
1.8
Low-level output current, IOL
Operating free-air temperature, TA
–40
MAX
UNIT
40
V
3
mA
85
°C
electrical characteristics, VCC = 3 V, TA = 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
Vs
SENSE input voltage
Is
SENSE input current
4V
Vs = 0
0.4
ICC
Supply current
VCC = 40 V,
IOL = 1.5 mA
TA = –40°C to 85°C
VOL
Low level output voltage
Low-level
IOH
ICT
High-level output current
IOL = 3 mA
VOH = 40 V,
Timing-capacitor charge current
Vs = 0.6 V
MIN
TYP
MAX
495
500
505
490
2
TA = –40°C to 85°C
Vs = 0.6 V,
No load
510
2.5
1.5
3
3.5
0.6
1
0.4
0.8
Vs = 0.6 V,
UNIT
mV
µA
mA
V
1
µA
11
15
19
µA
MIN
TYP
MAX
1
1.5
ms
TA = –40°C to 85°C
switching characteristics, VCC = 3 V, TA = 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
UNIT
tpi
tpo
SENSE pulse duration
CT = 0.01 µF
2
Output pulse duration
CT = 0.01 µF
0.5
tr
tf
Output rise time
CT = 0.01 µF,
RL = 2.2 kΩ,
CL = 100 pF
15
µs
Output fall time
CT = 0.01 µF,
RL = 2.2 kΩ,
CL = 100 pF
0.5
µs
tpd
Propagation delay time, SENSE to output
CT = 0.01 µF
10
µs
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µs
3
TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
PARAMETER MEASUREMENT INFORMATION
–
A
+
VCC
Vs
SENSE
0.6 V
VCC
GND
Figure 1. VCC vs ICC Measurement Circuit
VCC
Vs
SENSE
CT
VCC
+
0.6 V
A
GND
–
Figure 2. VCC vs ICT
Test
Point
VCC
RESET
Vs
3V
SENSE
CT
0.4 V
GND
0.01 µF
Figure 3. IOL vs VOL
4
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TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
PARAMETER MEASUREMENT INFORMATION
2.2 kΩ
VCC
Test
Point
RESET
+
A
–
Vs
VCC
SENSE
CT
Vs
GND
0.01 µF
Figure 4. VS, IS Characteristics
2.2 kΩ
VCC
Test
Point
RESET
Vs
3V
SENSE
CT
GND
100 pF
Ct
Figure 5. Switching Characteristics
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5
TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
SUPPLY CURRRENT
vs
SUPPLY VOLTAGE
I CC – Supply Current – mA
1.2
1.0
0.8
TA = 85_C
TA = 25_C
TA = –40_C
0.6
0.4
0.2
0
0
10
20
30
40
50
60
Timing-Capacitor Charge Current Supply – mV
TYPICAL CHARACTERISTICS†
TIMING-CAPACITOR CHARGE CURRENT
vs
SUPPLY VOLTAGE
16
TA = –40_C
15
14
TA = 25_C
13
TA = 85_C
12
11
10
0
10
20
40
50
60
Figure 7
Figure 6
VOL
vs
IOL
SENSE INPUT VOLTAGE
vs
TEMPERATURE
506
1.2
TA = 25_C
VS = 500.8 mV
504
1.0
Vs – Sense Input Voltage – mV
VOL – Low-Level Output Voltage – V
30
VCC – Supply Voltage – V
VCC – Supply Voltage – V
TA = 85_C
0.8
0.6
TA = 25_C
0.4
TA = –40_C
0.2
502
500
498
496
TA = 25_C
VS = 498.3 mV
494
492
490
0
0
1
2
3
4
5
6
488
–75 –50 –25
0
IOL – Low-Level Output Current – mA
Figure 9
Figure 8
† Data at high and low temperatures are applicable only within the recommended operating conditions.
6
25
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75 100 125 150
TA – Free-Air Temperature – °C
• DALLAS, TEXAS 75265
TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
TYPICAL CHARACTERISTICS†
SENSE INPUT CURRENT
vs
SENSE INPUT VOLTAGE
3.4
3.5
3.2
3.0
I s – Sense Input Current – µ A
I s – Sense Input Current – µ A
SENSE INPUT CURRENT
vs
TEMPERATURE
3.0
2.8
2.6
2.4
2.2
2.0
2.5
2.0
1.5
1.0
0.5
0
–0.5
1.8
1.6
–75 –50 –25
–1.0
0
25
50
0
75 100 125 150
TA – Free-Air Temperature – °C
0.1 0.2 0.3 0.4 0.5 0.6 1.0 10
Vs – Sense Input Voltage – V
Figure 10
Figure 11
OUTPUT PULSE DURATION
vs
TIMING CAPACATOR
109
t po – Output Pulse Duration – µ s
40
108
107
106
105
104
103
102
101
1
1
101 102 103 104 105 106 107 108 109
Ct – Timing Capacitor – pF
Figure 12
† Data at high and low temperatures are applicable only within the recommended operating conditions.
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TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
TYPICAL CHARACTERISTICS
2.2 kΩ
240 kΩ
VCC
Test
Point 2
RESET
Vs
SENSE
6V
CT
30 kΩ
TP1
Y-Axis (TP1) = 1 V/Division
Y-Axis (TP2) = 2 V/Division
Test
Point 1
TP2
GND
100 pF
510 pF
X-Axis = 0.2 ms/Division
Test
Point 1
2.2 kΩ
240 kΩ
VCC
RESET
Vs
Test
Point 2
SENSE
6V
CT
30 kΩ
Figure 14. VCC vs Output Waveform 1
TP1
Y-Axis (TP1) = 1 V/Division
Y-Axis (TP2) = 2 V/Division
Figure 13. VCC vs Output Test Circuit 1
TP2
GND
100 pF
510 pF
X-Axis = 0.2 ms/Division
Figure 15. VCC vs Output Test Circuit 2
8
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Figure 16. VCC vs Output Waveform 2
• DALLAS, TEXAS 75265
TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
TYPICAL CHARACTERISTICS
2.2 kΩ
240 kΩ
VCC
Test
Point 2
RESET
Vs
SENSE
CT
30 kΩ
TP1
Y-Axis (TP1) = 1 V/Division
Y-Axis (TP2) = 2 V/Division
Test
Point 1
TP2
GND
100 pF
510 pF
X-Axis = 0.2 ms/Division
Figure 18. VCC vs Output Waveform 3
Figure 17. VCC vc Output Test Circuit 3
detailed description
sense-voltage setting
The sense voltage, Vs, of the TL7700 typically is 500 mV. By using two external resistors, the circuit designer
can obtain any sense voltage over 500 mV. In Figure 19, the sensing voltage, V′s, is calculated as:
V′s = Vs × (R1 + R2)/R2
Where:
Vs = 500 mV, typically at TA = 25°C
At room temperature, Vs has a variation of 500 mV ± 5 mV. In the basic circuit shown in Figure 19, variations
of [±5 × (R1 + R2)/R2] mV are superimposed on Vs.
VCC
RL
VCC
R1
RESET
Vs
RESET
SENSE
CT
R2
GND
Ct
GND
Figure 19
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TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
sense-voltage hysteresis setting
If the sense voltage, Vs, does not have hysteresis in it and the voltage on the sensing line contains ripples, the
resetting of TL7700 will be unstable. Hysteresis is added to the sense voltage to prevent such problems. As
shown in Figure 20, the hysteresis, Vhys, is added, and the value is determined as:
Vhys = Is × R1
Where:
Is = 2.5 µA, typically at TA = 25°C
At room temperature, Is has variations of 2.5 µA ± 0.5 µA. Therefore, in the circuit shown in Figure 19, Vhys has
variations of (±0.5 × R1) µV. In circuit design, it is necessary to consider the voltage-dividing resistor tolerance
and temperature coefficient in addition to variations in Vs and Vhys.
VCC
Vhys
Vs
1.5 V
T
RESET
tpo
tpo
T
Figure 20. VCC-RESET Timing Chart
output pulse-duration setting
Constant-current charging starts on the timing capacitor when the sensing-line voltage reaches the TL7700
sense voltage. When the capacitor voltage exceeds the threshold level of the output drive comparator, RESET
changes from a low to a high level. The output pulse duration is the time between the point when the sense-pin
voltage exceeds the threshold level and the point when the RESET output changes from a low level to a high
level. When the TL7700 is used for system power-on reset, the output pulse duration, tpo, must be set longer
than the power rise time. The value of tpo is:
tpo = Ct × 105 seconds
Where:
Ct is the timing capacitor in farads
There is a limit on the device response speed. Even if Ct = 0, tpo is not 0, but approximately 5 µs to 10 µs.
Therefore, when the TL7700 is used as a comparator with hysteresis, without connecting Ct, switching speeds
(tr/tf, tpo/tpd, etc.) must be considered.
10
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Copyright  1999, Texas Instruments Incorporated