M48Z35 M48Z35Y 256 Kbit (32 Kbit x 8) ZEROPOWER® SRAM Features ■ Integrated, ultra low power SRAM, power-fail control circuit, and battery ■ READ cycle time equals WRITE cycle time ■ Automatic power-fail chip deselect and WRITE protection ■ WRITE protect voltages: (VPFD = power-fail deselect voltage) – M48Z35: VCC = 4.75 to 5.5 V; 4.5 V ≤ VPFD ≤ 4.75 V – M48Z35Y: 4.5 to 5.5 V; 4.2 V ≤ VPFD ≤ 4.
Contents M48Z35, M48Z35Y Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1 READ mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 WRITE mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.
M48Z35, M48Z35Y List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 READ mode AC characteristics . . .
List of figures M48Z35, M48Z35Y List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. 4/24 Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 DIP connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 SOIC connections . . . . . .
M48Z35, M48Z35Y 1 Description Description The M48Z35/Y ZEROPOWER® RAM is a 32 K x 8, non-volatile static RAM that integrates power-fail deselect circuitry and battery control logic on a single die. The monolithic chip is available in two special packages to provide a highly integrated battery-backed memory solution. The M48Z35/Y is a non-volatile pin and function equivalent to any JEDEC standard 32 K x 8 SRAM.
Description M48Z35, M48Z35Y Table 1. Signal names A0-A14 Address inputs DQ0-DQ7 Figure 2. Data inputs / outputs E Chip enable input G Output enable input W WRITE enable input VCC Supply voltage VSS Ground DIP connections A14 A12 A7 A6 A5 A4 A3 A2 A1 A0 DQ0 DQ1 DQ2 VSS 28 1 27 2 26 3 4 25 24 5 23 6 7 M48Z35 22 8 M48Z35Y 21 20 9 19 10 18 11 17 12 13 16 14 15 VCC W A13 A8 A9 A11 G A10 E DQ7 DQ6 DQ5 DQ4 DQ3 AI01617D Figure 3.
M48Z35, M48Z35Y Figure 4.
Operating modes 2 M48Z35, M48Z35Y Operating modes The M48Z35/Y also has its own power-fail detect circuit. The control circuitry constantly monitors the single 5 V supply for an out of tolerance condition. When VCC is out of tolerance, the circuit write protects the SRAM, providing a high degree of data security in the midst of unpredictable system operation brought on by low VCC.
M48Z35, M48Z35Y Figure 5. Operating modes READ mode AC waveforms tAVAV VALID A0-A14 tAVQV tAXQX tELQV tEHQZ E tELQX tGLQV tGHQZ G tGLQX DQ0-DQ7 VALID AI00925 Note: WRITE enable (W) = High. Table 3.
Operating modes 2.2 M48Z35, M48Z35Y WRITE mode The M48Z35/Y is in the WRITE mode whenever W and E are low. The start of a WRITE is referenced from the latter occurring falling edge of W or E. A WRITE is terminated by the earlier rising edge of W or E. The addresses must be held valid throughout the cycle. E or W must return high for a minimum of tEHAX from chip enable or tWHAX from WRITE enable prior to the initiation of another READ or WRITE cycle.
M48Z35, M48Z35Y Table 4.
Operating modes Figure 8. M48Z35, M48Z35Y Power down/up mode AC waveforms VCC VPFD (max) VPFD (min) VSO tF tR tFB tRB tDR tPD INPUTS trec DON'T CARE RECOGNIZED RECOGNIZED HIGH-Z OUTPUTS VALID VALID (PER CONTROL INPUT) (PER CONTROL INPUT) AI01168C Table 5.
M48Z35, M48Z35Y 2.4 Operating modes VCC noise and negative going transients ICC transients, including those produced by output switching, can produce voltage fluctuations, resulting in spikes on the VCC bus. These transients can be reduced if capacitors are used to store energy which stabilizes the VCC bus. The energy stored in the bypass capacitors will be released as low going spikes are generated or energy will be absorbed when overshoots occur. A ceramic bypass capacitor value of 0.
Maximum ratings 3 M48Z35, M48Z35Y Maximum ratings Stressing the device above the rating listed in the absolute maximum ratings table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 7.
M48Z35, M48Z35Y 4 DC and AC parameters DC and AC parameters This section summarizes the operating and measurement conditions, as well as the DC and AC characteristics of the device. The parameters in the following DC and AC characteristic tables are derived from tests performed under the measurement conditions listed in Table 8: Operating and AC measurement conditions. Designers should check that the operating conditions in their projects match the measurement conditions when using the quoted parameters.
DC and AC parameters Table 10. DC characteristics Symbol Parameter ILI(2) ILO (2) Input leakage current Output leakage current M48Z35, M48Z35Y Test condition(1) Min Max Unit 0 V ≤ VIN ≤ VCC ±1 µA 0 V ≤ VOUT ≤ VCC ±5 µA Outputs open 50 mA E = VIH 3 mA E = VCC – 0.2 V 3 mA ICC Supply current ICC1 Supply current (standby) TTL ICC2 Supply current (standby) CMOS VIL Input low voltage –0.3 0.8 V VIH Input high voltage 2.2 VCC + 0.3 V VOL Output low voltage IOL = 2.
M48Z35, M48Z35Y 5 Package mechanical data Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. Figure 11. PCDIP28 – 28-pin plastic DIP, battery CAPHAT™, package outline A2 A1 B1 B A L C e1 eA e3 D N E 1 PCDIP Note: Drawing is not to scale.
Package mechanical data M48Z35, M48Z35Y Figure 12. SOH28 – 28-lead plastic small outline, battery SNAPHAT®, pack. outline A2 A C B eB e CP D N E H A1 α L 1 SOH-A Note: Drawing is not to scale. Table 12. SOH28 – 28-lead plastic small outline, battery SNAPHAT®, pack. mech. data mm inches Symbol Typ Min A Typ Min Max 3.05 0.120 A1 0.05 0.36 0.002 0.014 A2 2.34 2.69 0.092 0.106 B 0.36 0.51 0.014 0.020 C 0.15 0.32 0.006 0.012 D 17.71 18.49 0.697 0.728 E 8.
M48Z35, M48Z35Y Package mechanical data Figure 13. SH – 4-pin SNAPHAT® housing for 48 mAh battery, package outline A1 A2 A eA A3 B L eB D E SHZP-A Note: Drawing is not to scale. Table 13. SH – 4-pin SNAPHAT® housing for 48 mAh battery, pack. mech. data mm inches Symbol Typ Min A Max Typ Min 9.78 Max 0.385 A1 6.73 7.24 0.265 0.285 A2 6.48 6.99 0.255 0.275 A3 0.38 0.015 B 0.46 0.56 0.018 0.022 D 21.21 21.84 0.835 0.860 E 14.22 14.99 0.560 0.590 eA 15.
Package mechanical data M48Z35, M48Z35Y Figure 14. SH – 4-pin SNAPHAT® housing for 120 mAh battery, package outline A1 A2 A eA A3 B L eB D E SHZP-A Note: Drawing is not to scale. Table 14. SH – 4-pin SNAPHAT® housing for 120 mAh battery, pack. mech. data mm inches Symb Typ Min A Typ Min 10.54 Max 0.415 A1 8.00 8.51 0.315 0.335 A2 7.24 8.00 0.285 0.315 A3 20/24 Max 0.38 0.015 B 0.46 0.56 0.018 0.022 D 21.21 21.84 0.835 0.860 E 17.27 18.03 0.680 0.
M48Z35, M48Z35Y 6 Part numbering Part numbering Table 15. Ordering information scheme Example: M48Z 35Y –70 MH 1 E Device type M48Z Supply voltage and write protect voltage 35(1) = VCC = 4.75 to 5.5 V; VPFD = 4.5 to 4.75 V 35Y = VCC = 4.5 to 5.5 V; VPFD = 4.2 to 4.5 V Speed –70 = 70 ns Package PC = PCDIP28 MH(2) = SOH28 Temperature range 1 = 0 to 70 °C Shipping method For SOH28: E = Lead-free ECOPACK® package, tubes F = Lead-free ECOPACK® package, tape & reel For PCDIP28: blank = Tubes 1.
Environmental information 7 M48Z35, M48Z35Y Environmental information Figure 15. Recycling symbols This product contains a non-rechargeable lithium (lithium carbon monofluoride chemistry) button cell battery fully encapsulated in the final product. Recycle or dispose of batteries in accordance with the battery manufacturer's instructions and local/national disposal and recycling regulations.
M48Z35, M48Z35Y 8 Revision history Revision history Table 17. Document revision history Date Revision Aug-1999 1 Changes First issue 21-Apr-2000 1.1 10-May-2001 2 SH and SH28 packages for 2-pin and 2-socket removed 29-May-2002 2.1 02-Apr-2003 3 v2.
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