S-1701 Datasheet, PDF (48/70 Pages) Seiko Instruments Inc – HIGH RIPPLE-REJECTION LOW DROPOUT CMOS VOLTAGE REGULATOR WITH RESET FUNCTION

HIGH RIPPLE-REJECTION LOW DROPOUT CMOS VOLTAGE REGULATOR WITH RESET FUNCTION
S-1701 Series
Rev.2.4_00
„ Application Circuit
If the desired detection voltage range is other than those provided by the S-1701 Series, the detection voltage
can be changed by using a divided resistor or diode in the SENSE pin products (N/ P/ Q/ R/ S/ T types) as
shown in Figures 38 and 39.
In the case shown in Figure 38, the hysteresis width also changes at the same time.
1. Changing detection voltage using divided resistors
VDD
R_a^*1
(R_a ≤ 75 kΩ)
SENSE
S-1701 Series
N to T types
R_b
VDD
VDOUT
VSS
Detection voltage =
R_a + R_b
R_b
• −V_DET
Hysteresis width =
R_a + R_b
R_b
• V_HYS
*1. Set R_a to 75 kΩ or lower to prevent oscillation.
Figure 38
Caution If R_a and R_b are larger, the hysteresis may be greater than the result of the above
formula due to the through current of the IC.
2. Changing detection voltage using diode
VDD
V_f1
V_f2
SENSE _{S-1701 Series}
N to T types
VDD
VDOUT
VSS
Detection voltage = V_f1 + V_f2 + (−V_DET)
Figure 39
Caution The above connection diagrams (Figures 38 and 39) and constants will not
guarantee successful operation. Perform thorough evaluation using the actual
application to set the constants.
48
Seiko Instruments Inc.