HIGH RIPPLE-REJECTION LOW DROPOUT CMOS VOLTAGE REGULATOR WITH RESET FUNCTION
Rev.3.0_00 S-1701 Series
Seiko Instruments Inc. 45
5. S-1701 Series N/P/Q types
The S-1701 Series N/P/Q types do not provide an ON/OFF function because the ON/OFF pin is connected to the VIN
pin in the circuit.
The detector block features the external SEN SE pin, which allo ws monitoring of oth er power sup plies. T he SENSE p in
is configured onl y by a resistor, so instanta neous current such as through-type current does not flow through this pin.
This allows pre cise monitoring of the in put power supply by connecting the SENSE pin to the input power supply even
when a resistor (RIN) is connected bet ween the input po wer supply and the VIN pin. The bui lt-in counter timer allows
selection of the release dela y time from three settings (N: No delay (60 μs), P: 50 ms, Q: 100 ms).
The power supply is shared by the regul ator block and detector block and supplied from the VIN pin, so care must be
taken concerning the VIN pin input impedance*1.
6. S-1701 Series R/S/T types
In the S-1701 Series R/S/T types, the VDOUT pin, which is the output pin of the detector, is c onnected to the ON/OFF
pin of the regulator in the circuit. This allows setting of the regulator to the standby mode at the same time as the
VDOUT pin outputs a RESET signal.
The detector block featur es an external SEN SE pin, which allows monitoring of other power suppl ies. The SENSE pi n
is configured onl y by a resistor, so instanta neous current such as through-type current does not flow through this pin.
This allows pre cise monitoring of the in put power supply by connecting the SENSE pin to the input power supply even
when a resistor (RIN) is connected bet ween the input po wer supply and the VIN pin. The bui lt-in counter timer allows
selection of the release dela y time from three settings (R: No delay (60 μs), S: 50 ms, T: 100 ms).
The power supply is shared by the regul ator block and detector block and supplied from the VIN pin, so care must be
taken concerning the VIN pin input impedance*1.
7. S-1701 Series U/V/W types
The S-1701 Series U/V/W t ypes do not provide an ON/OFF function because the ON/OF F pin is connec ted to the VIN
pin in the circuit.
The SENSE pin is connected to the VOUT pin, which is an output pin of the regulator, in the internal circuit of the
detector block, so the output voltage of the regulator (VOUT) is monitored a nd a reset signal is output from the VDOUT
pin*2. The built-in counter timer allo ws selection of the release delay time from three settings (U: No de lay (60 μs), V:
50 ms, W: 100 ms).
The power supply is shared by the regul ator block and detector block and supplied from the VIN pin, so care must be
taken concerning the VIN pin input impedance*1.
8. S-1701 Series X/Y/Z types
The S-1701 Series X/Y/Z types do not provide an ON/OFF f unction because the ON/OFF pin is connected to the VIN
pin in the circuit.
The SENSE pin is connected to the VIN pin in the internal circuit of the detector block, so the voltage applied to the
VIN pin is monitored and a reset signal is output from the VDOUT pin. The built-in counter timer allows selection of the
release delay time from three settings ( X: No dela y (60 μs), Y: 50 ms, Z: 100 ms).
The power supply is shared by the regul ator block and detector block and supplied from the VIN pin, so care must be
taken concerning the VIN pin input impedance*1.