TL7700 Datasheet, PDF (9/11 Pages) STMicroelectronics – SUPPLY VOLTAGE SUPERVISORS

TL7700
SUPPLY-VOLTAGE SUPERVISOR
SLVS220A – JULY 1999 – REVISED NOVEMBER 1999
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 vc 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 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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