BQ2201PNG4

Overview

The bq2201PNG4 is a CMOS SRAM Nonvolatile Controller Unit designed for 3-volt battery-backup applications. It provides power monitoring and switching to convert standard CMOS SRAM into nonvolatile read/write memory. The device features a precision comparator that monitors the 5V VCC input, forcing the conditioned chip-enable output inactive during out-of-tolerance conditions to write-protect the SRAM. During power failure, it switches the external SRAM from the VCC supply to one of two 3V backup supplies via BC1 and BC2 inputs. The unit ensures data retention with less than 10ns chip-enable propagation delay and includes configurable threshold select options for 5% or 10% supply operation.

Feature Summary

• Provides hardware-based conversion of standard CMOS SRAM into nonvolatile memory through automatic power-fail detection and switching.
• Monitors the primary 5V supply and unconditionally write-protects connected SRAM when voltage drops below a selectable threshold.
• Manages dual 3V primary backup cell inputs with automatic isolation switching between cells based on voltage levels.
• Includes an internal isolation mechanism to prevent battery drain when no valid data needs to be retained.

Applications

• Battery-backed static RAM systems requiring nonvolatile data retention
• Industrial control units needing reliable memory protection during power fluctuations
• Embedded systems utilizing standard CMOS SRAM with 3V lithium backup cells

Procurement Notes

Verify the specific package configuration matches the design requirements, as the bq2201 family is available in multiple pinouts including 8-pin narrow DIP and SOIC variants. Confirm the temperature range designation aligns with the operational environment, distinguishing between commercial and industrial grades. Ensure the ordering suffix correctly reflects the intended package type and thermal rating before finalizing procurement orders.

Selection Notes

Select this component when designing systems that require seamless transition between main power and 3V backup sources for SRAM retention. Consider the threshold select pin configuration to match the required power-fail detection sensitivity for either 5% or 10% supply tolerance. Evaluate the need for dual backup cell support if extended data retention is necessary beyond the capacity of a single primary cell.

Part Context

The bq2201 belongs to Texas Instruments' portfolio of power management and battery backup controllers. This specific part number denotes the commercial grade version housed in an 8-pin narrow plastic DIP package. It serves as a dedicated interface solution for preserving volatile memory states without requiring complex software intervention during power interruptions.

Replacement Considerations

Check for updated revisions within the bq2201 series or alternative TI SRAM controller ICs that offer compatible pinouts and electrical characteristics. Verify that any substitute maintains the same 3V backup input compatibility and propagation delay specifications to ensure system integrity.