Texas Instruments BQ2205LYPWR

Overview

BQ2205LYPWR from Texas Instruments is a CMOS SRAM non-volatile controller with integrated reset, designed to convert standard CMOS SRAM into battery-backed non-volatile memory. It supports one or two banks of SRAM, provides 3.3-V operation with 3-V primary cell backup, delivers <20-ns chip-enable propagation delay, and features dual conditioned CE outputs (CECON1/CECON2) for hardware write-protection during power failure - used in NVSRAM modules and industrial embedded systems.

For engineers reviewing the BQ2205LYPWR datasheet, BQ2205LYPWR pinout, BQ2205LYPWR application, or BQ2205LYPWR equivalent, key selection considerations include VPFD = 2.9 V (typ), tCER = 30–85 ms write-protect hold time after power-up, VOUT switching between VCC and BCP, open-drain RST/BW outputs, and TSSOP-16 package compatibility with space-constrained PCB layouts.

Technical Context

The BQ2205LYPWR implements autonomous power-fail detection using a precision comparator monitoring VCC against VPFD (2.85–2.95 V). When VCC falls below VPFD, it forces CECON1 and CECON2 inactive and switches VOUT from VCC to the backup supply (BCP) within defined slew-rate constraints (tF ≤ 300 µs, tR ≤ 100 µs).

During power-up, VOUT reverts to VCC once VCC exceeds VPFD; CECON1/CECON2 remain inactive for tCER (30–85 ms) regardless of CE input to ensure CPU stabilization. Bank selection via A input enables hardware decoding across two SRAM banks without external logic.

Key Specifications

Pinout & Package

Package: 16-pin TSSOP (PW), 4.4 mm × 5.0 mm body, 0.65 mm pitch, 1.2 mm max height, JEDEC MO-153 compliant, RoHS-compliant NIPDAU lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SRAM non-volatile controller applications.

Compared with MAX6900EAP+ and DS1230Y-120, the BQ2205LYPWR uniquely combines dual-bank hardware decoding, sub-20-ns CE propagation, and 150-nA backup current in a 4.4-mm-wide TSSOP - making it optimal for space-constrained, high-reliability industrial SRAM backup where firmware-independent protection is mandatory.

Availability

BQ2205LYPWR is available at Aetrix Electronics and suitable for NVSRAM modules, point-of-sale terminals, and medical instrumentation requiring stable component supply across extended product lifecycles.

Supply support for BQ2205LYPWR 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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.

The BQ2205LYPWR belongs to TI's non-volatile memory interface controller product line, engineered specifically to replace battery-backed SRAM modules with discrete, reliable, and layout-efficient hardware supervision - targeting applications where data integrity during power disruption is non-negotiable.

FAQ

What is the function of the A pin on the BQ2205LYPWR?

The A pin on the BQ2205LYPWR is a bank-select input that determines whether the CE signal is routed to CECON1 (A = low) or CECON2 (A = high) during valid-power operation. This enables hardware-based decoding of two independent SRAM banks without external logic, simplifying memory expansion in systems like POS terminals and industrial controllers. The A pin has ±1 µA leakage and operates across the full −0.3 V to VCC + 0.3 V input range.

Does the BQ2205LYPWR support rechargeable backup batteries?

No, the BQ2205LYPWR is explicitly designed for non-rechargeable 3-V primary cells (e.g., lithium thionyl chloride) connected to the BCP pin. Its internal circuitry lacks charge control or overvoltage protection for rechargeable chemistries. Using a rechargeable battery risks overdischarge, reverse polarity damage, or premature failure - the BQ2205LYPWR datasheet specifies 2.0–4.0 V BCP range and warns against charging circuits.

How does the BQ2205LYPWR handle power-up sequencing with the RST output?

The BQ2205LYPWR asserts RST low when VCC rises above VPFD (2.85–2.95 V) and holds it active for tRST = 30–85 ms, providing a clean, synchronized power-on reset to the system CPU. RST is open-drain and requires an external pull-up; TI recommends ≤10 kΩ if a push-button reset is also used. This ensures the microprocessor remains held in reset until internal comparators stabilize and VOUT completes switchover.

Can the BQ2205LYPWR operate with a 2.5-V main supply?

No, the BQ2205LYPWR requires a minimum VCC of 3.0 V per its recommended operating conditions. Operation below 3.0 V violates specification and may cause unreliable VPFD detection, incomplete VOUT switching, or undefined CECONx behavior. Systems with 2.5-V rails must use level-shifting or select alternative controllers rated for lower VCC, as the BQ2205LYPWR is strictly a 3.3-V domain device.

What is the purpose of the BW pin on the BQ2205LYPWR?

The BW (Battery Warning) pin on the BQ2205LYPWR is an open-drain output that latches low during power-up if the backup cell voltage falls below VBW = 0.677 × VCC, indicating insufficient battery capacity for reliable non-volatile operation. It remains asserted until next power cycle, enabling field-service alerts or host MCU logging. BW has 0.4-V max VOL at 1 mA and must be pulled up externally.