M48T201Y Datasheet, PDF (19/33 Pages) STMicroelectronics – 3.3V-5V TIMEKEEPER CONTROLLER

M48T201Y, M48T201V
Power-on Reset
The M48T201Y/V continuously monitors V_CC.
When V_CC falls to the power fail detect trip point,
the RST pulls low (open drain) and remains low on
power-up for t_REC after V_CC passes V_PFD (max).
The RST pin is an open drain output and an appro-
priate pull-up resistor to V_CC should be chosen to
control rise time.
Reset Inputs (RSTIN1 & RSTIN2)
The M48T201Y/V provides two independent in-
puts which can generate an output reset. The du-
ration and function of these resets is identical to a
reset generated by a power cycle. Figure 10 and
Table 8 illustrate the AC reset characteristics of
this function. Pulses shorter than t_R1 and t_R2 will
not generate a reset condition. RSTIN1 and
RSTIN2 are each internally pulled up to V_CC
through a 100KΩ resistor.
Figure 10. RSTIN1 and RSTIN2 Timing Waveforms
RSTIN1
RSTIN2
RST
tR1
tR2
Hi-Z
tR1HRZ
Hi-Z
tR2HRZ
AI01679
Table 8. Reset AC Characteristics
Symbol
Parameter⁽¹⁾
Min
Max
t_R1
RSTIN1 Low to RST Low
50
200
t_R2
RSTIN2 Low to RST Low
20
100
t_R1HRZ(2)
RSTIN1 High to RST Hi-Z
40
200
t_R2HRZ(2)
RSTIN2 High to RST Hi-Z
40
200
Note: 1. Valid for Ambient Operating Temperature: TA = 0 to 70°C; VCC = 4.5 to 5.5V or 3.0 to 3.6V (except where noted).
2. C_L = 5pF (see Figure 14., page 25).
Unit
ns
ms
ms
ms
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