HANBit
HMNR28D(V)
5.0 or 3.3V, 16K bit (2 Kbit x 8) TIMEKEEPER NVSRAM
Part No. HMNR28D(V)
GENERAL DESCRIPTION
The HMNR28D(V) TIMEKEEPER SRAM is a 2Kb x 8 non-volatile static RAM and real time clock organized as 2,048
words by 8 bits. The special DIP package provides a fully integrated battery back-up memory and real time clock solution.
The HMNR28D(V) directly replaces industry standard 2Kbit x 8 SRAMs. It also provides the non-volatility of Flash without
any requirement for special WRITE timing or limitations on the number of WRITEs that can be performed.
FEATURES
■ INTEGRATED LOW POWER SRAM, REAL TIME CLOCK, POWER-FAIL CONTROL CIRCUIT, BATTERY and
CRYSTAL
■ BCD CODED YEAR, MONTH, DAY, DATE, HOURS, MINUTES, and SECONDS
■ AUTOMATIC POWER-FAIL CHIP DESELECT and WRITE PROTECTION VOLTAGES :
(VPFD = Power-fail Deselect Voltage)
– HMNR28D : VCC = 4.5 to 5.5V
4.2V ≤ VPFD ≤ 4.5V
– HMNR28DV: VCC = 3.0 to 3.6V
2.7V ≤ VPFD ≤ 3.0V
■ CONVENTIONAL SRAM OPERATION : UNLIMITED WRITE CYCLES
■ SOFTWARE CONTROLLED CLOCK CALIBRATION FOR HIGH ACCURACY APPLICATIONS
■ 10 YEARS OF DATA RETENTION and CLOCK OPERATION IN THE ABSENCE OF POWER PIN and FUNCTION
COMPATIBLE WITH INDUSTRY STANDARD 2K x 8 SRAMS
■ SELF-CONTAINED BATTERY and CRYSTAL IN DIP PACKAGE
OPTIONS
w Timing
70 ns
MARKING
PIN ASSIGNMENT
-70
-85
A7
A6
A5
Vcc
A8
A9
1
2
3
4
24
23
22
21
85 ns
A4
/WE
/OE
A10
/CE
DQ7
DQ6
DQ5
DQ4
DQ3
A3
A2
A1
A0
DQ0
DQ1
DQ2
Vss
6
7
8
19
18
17
16
15
14
13
9
10
11
12
24-pin Encapsulated Package
URL : www.hbe.co.kr
Rev. 0.0 (March, 2002)
1
HANBit Electronics Co.,Ltd.
HANBIT [ HANBIT ELECTRONICS CO.,LTD ]
