l4948 STMicroelectronics, l4948 Datasheet - Page 7

• Manufacturer Part Number: l4948
• Description: Quad Voltage Regulator With Inhibit And Reset
• Manufacturer: STMicroelectronics

The STCAP pin acts like a delay circuit. Due to
the large capacitor (470 F), the STCAP pin allows
the battery voltage to decay slowly giving the mi-
croprocessor time to store data. Also, during short
low voltage or negative voltage conditions, the
STCAP pin protects the 5V st-by output from
dropping below the RESET and LVW trip points
The four outputs are expected to follow the bat-
tery voltage down to 7V. At 7V typical the LVW
tells the microprocessor to stop operation and
Graphs of the Output Curves for V
Notes and Information
The following information is for clarification, not for specification definition.
Please use the information in this way.
O1,2,3 and 4 (Cont.)
save operating data Below 7V the outputs are ex-
pected to stay alive and ready for a return of bat-
tery.
The L4948 has a st-by mode to keep the micro-
processor and memories allive during an ignition
off conditions. The ON/OFF input pin in controlled
by the microprocessor. An high on the ON/OFF
pin places the part in normal mode. A low on the
ON/OFF pin places the part in st-by mode.V
V
02
, V
03
will be off during st-by mode.
L4948
7/9
01
,