M48T201V-70MH1TR STMICROELECTRONICS [STMicroelectronics], M48T201V-70MH1TR Datasheet - Page 21

• Manufacturer Part Number: M48T201V-70MH1TR
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

3.8
3.9
3.10
Power-on reset
The M48T201Y/V continuously monitors V
point, the RST pulls low (open drain) and remains low on power-up for t
passes V
to V
Reset inputs (RSTIN1 & RSTIN2)
The M48T201Y/V provides two independent inputs which can generate an output reset. The
duration and function of these resets is identical to a reset generated by a power cycle.
Figure 9
than t
pulled up to V
Figure 9.
Table 8.
1. Valid for Ambient Operating Temperature: T
2. C
Calibrating the clock
The M48T201Y/V is driven by a quartz controlled oscillator with a nominal frequency of
32,768Hz. The devices are factory calibrated at 25°C and tested for accuracy. Clock
accuracy will not exceed ±35 ppm (parts per million) oscillator frequency error at 25°C,
which equates to about ±1.53 minutes per month. When the Calibration circuit is properly
employed, accuracy improves to better than +1/–2 ppm at 25°C.
t
t
Symbol
noted).
R1HRZ
R2HRZ
CC
L
t
t
R1
= 5pF (see
R1
R2
should be chosen to control rise time.
RSTIN1
RSTIN2
RST
and t
(2)
(2)
and
PFD
RSTIN1 and RSTIN2 timing waveforms
Reset AC characteristics
Table 8
(max). The RST pin is an open drain output and an appropriate pull-up resistor
R2
CC
RSTIN1 Low to RST Low
RSTIN2 Low to RST Low
RSTIN1 High to RST Hi-Z
RSTIN2 High to RST Hi-Z
Figure 13 on page
will not generate a reset condition. RSTIN1 and RSTIN2 are each internally
through a 100K
illustrate the AC reset characteristics of this function. Pulses shorter
tR1
27).
Parameter
resistor.
A
= 0 to 70°C; V
(1)
CC
tR1HRZ
. When V
Hi-Z
tR2
CC
= 4.5 to 5.5V or 3.0 to 3.6V (except where
CC
falls to the power fail detect trip
Min
50
20
40
40
REC
tR2HRZ
Hi-Z
Max
200
100
200
200
after V
AI01679
CC
Unit
ms
ms
ms
ns
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