Infineon Technologies CY62157ELL-45ZSXIT

Overview

CY62157ELL-45ZSXIT from Cypress Semiconductor is an 8-Mbit (512 K × 16) CMOS static RAM with 45 ns access time, 4.5–5.5 V supply range, and industrial temperature rating (–40 °C to +85 °C). It features dual chip enables (CE1/CE2), byte-wide control (BHE/BLE), and ultra-low standby current (2 µA typical). Used in embedded controllers and portable instrumentation where deterministic timing and low-power retention are critical.

For engineers reviewing the CY62157ELL-45ZSXIT datasheet, CY62157ELL-45ZSXIT pinout, CY62157ELL-45ZSXIT application, or CY62157ELL-45ZSXIT equivalent, key selection criteria include TSOP II package compatibility, TTL-level I/O interface requirements, automatic power-down behavior under CE/BHE/BLE deassertion, and data retention at 2 V.

Technical Context

The CY62157ELL-45ZSXIT implements a 512K × 16 asynchronous SRAM array with independent high- and low-byte enables, enabling partial-word writes without read-modify-write cycles. Its dual CE architecture (CE1 active-low, CE2 active-low) supports hierarchical memory decoding in multi-chip systems.

It uses CMOS-compatible input thresholds (VIH ≥ 2.2 V, VIL ≤ 0.8 V) and delivers TTL-compatible outputs (VOH ≥ 2.4 V at –1 mA), making it interoperable with legacy 5 V microcontrollers but not with pure CMOS-input processors requiring VIH > 3.5 V.

Key Specifications

Pinout & Package

Package: 44-pin TSOP II (Type II, 400 mil width), JEDEC MO-141AC compliant, lead-free (Pb-free).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-Mbit asynchronous SRAM applications.

Compared with IS61LV51216AL-10TLI and AS6C4008-55TIN, the CY62157ELL-45ZSXIT uniquely balances 45 ns speed, 5 V TTL compatibility, dual CE, and byte enables-making it optimal for industrial upgrades of legacy 5 V systems without redesigning memory control logic.

Availability

CY62157ELL-45ZSXIT is available at Aetrix Electronics and suitable for industrial PLCs, portable medical monitors, automotive body control units, and test equipment requiring stable component supply across extended lifecycle programs.

Supply support for CY62157ELL-45ZSXIT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Cypress Semiconductor (now part of Infineon Technologies) is a fabless semiconductor company specializing in memory, microcontrollers, and connectivity solutions for industrial, automotive, and consumer markets.

The CY62157E MoBL® SRAM product line was designed specifically for battery-sensitive embedded systems requiring fast, deterministic, low-voltage data retention-targeting portable instrumentation, medical wearables, and energy-harvesting IoT nodes.

FAQ

Is CY62157ELL-45ZSXIT compatible with 3.3 V microcontrollers?

No. The CY62157ELL-45ZSXIT operates strictly at 4.5–5.5 V and uses TTL-level input thresholds (VIH ≥ 2.2 V). While its outputs can drive 3.3 V inputs, direct connection risks violating 3.3 V IOH/VOL specs and may cause excessive current leakage. Level-shifting circuitry is required for reliable 3.3 V interface.

What happens to data during power-down mode?

Data is retained as long as VCC remains ≥ 2 V and CE1 is HIGH or CE2 is LOW or both BHE and BLE are HIGH. At 2 V, ICCDR is ≤ 8 µA (industrial grade), allowing months of retention on a supercapacitor or coin cell. No external refresh or backup power circuitry is needed.

Can I use only CE1 and leave CE2 unconnected?

No. CE2 must be tied to a valid logic level: connect CE2 to VCC (to disable it permanently) or to a controlled signal. Leaving CE2 floating violates the ISB1/ISB2 specification and may cause unpredictable standby current or bus contention due to undefined internal state.

Does this SRAM support synchronous burst reads?

No. The CY62157ELL-45ZSXIT is purely asynchronous. All timing is referenced to address, CE, OE, and WE edges-not to a clock. Burst modes require external sequencing logic or a controller with built-in SRAM burst support; the device itself has no internal address counter or clock input.