Features: Power monitoring and switching for nonvolatile control of SRAMs
Write-protect control
Battery-low and battery-fail indicators
Reset output for system power-on reset
Input decoder for control of up to 2 banks of SRAM
3-volt primary cell input
3-volt rechargeable battery input/ outpu
Pinout
Specifications
| Symbol |
Parameter |
Value |
Unit |
Conditions |
| VCC |
DC voltage applied on VCC relative to VSS |
-0.3 to +7.0 |
V |
|
| VT |
DC voltage applied on any pin excluding VCC
relative to VSS |
-0.3 to +7.0 |
V |
VTVCC + 0.3 |
| TOPR |
Operating temperature |
0 to 70 |
|
Commercial |
| |
|
-40 to +85 |
|
"N" Industrial |
| TSTG |
Storage temperature |
-55 to +125 |
|
|
| TBIAS |
Temperature under bias |
-40 to +85 |
|
|
| TSOLDER |
Soldering temperature |
260 |
|
For 10 seconds |
| IOUT |
VOUT current |
200 |
mA |
|
DescriptionThe CMOS bq2203A SRAM Nonvolatile Controller With Battery Monitor provides all the necessary functions for converting one or two banks of standard CMOS SRAM into nonvolatile read/write memory. The bq2203A is compatible with the Personal Computer Memory Card International Association (PCMCIA) recommendations for battery-backed static RAM memory cards.
A precision comparator monitors of bq2203A the 5V VCC input for an out-of-tolerance condition. When out of tolerance is detected, the two conditioned chip-enable outputs are forced inactive to write-protect banks of SRAM.
Power for the external SRAMs bq2203A is switched from the VCC supply to the battery-backup supply as VCC decays. On a subsequent power-up, the VOUT supply is automatically switched from the backup supply to the VCC supply. The external SRAMs are write-protected until a powervalid condition exists. The reset output of bq2203A provides power-fail and power-on resets for the system. The battery monitor indicates battery-low and battery-fail conditions.
During power-valid operation, the input decoder of bq2203A selects one of two banks of SRAM.
bq2203A Data Sheet
