TL7700_07 Datasheet, PDF (9/17 Pages) Texas Instruments – SUPPLY-VOLTAGE SUPERVISOR

TL7700
SUPPLYĆVOLTAGE SUPERVISOR
SLVS220C − JULY 1999 − REVISED NOVEMBER 2004
TYPICAL CHARACTERISTICS
240 kΩ
VCC
RESET
Vs
SENSE
2.2 kΩ
Test
Point 2
Test
Point 1
TP1
TP2
30 kΩ
CT
GND
100 pF
510 pF
Figure 17. V_CC vs Output Test Circuit 3
X-Axis = 0.2 ms/Division
Figure 18. V_CC vs Output Waveform 3
detailed description
sense-voltage setting
The SENSE terminal input voltage, V_s, 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’ = V_s × (R1 + R2)/R2
Where:
V_s = 500 mV, typically at T_A = 25°C
At room temperature, V_s 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 V_s.
R1
VCC
Vs
SENSE
RESET
VCC
RL
RESET
CT
R2
GND
Ct
GND
Figure 19
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