Texas Instruments TL7700CPWRG4

Overview

TL7700CPWRG4 from Texas Instruments is a bipolar supply-voltage supervisor IC used as a reset controller in microcontroller, DSP, and FPGA systems. It features an adjustable 500 mV (±1%) sense threshold, 1.8 V to 40 V wide supply range, –40°C to 85°C operating temperature, 0.6 mA typical supply current at 40 V, and open-collector RESET output with 5 ms minimum pulse duration via external timing capacitor.

For engineers reviewing the TL7700CPWRG4 datasheet, TL7700CPWRG4 pinout, TL7700CPWRG4 application, or TL7700CPWRG4 equivalent, key selection considerations include its adjustable hysteresis via external resistors, precision internal voltage reference, timing-capacitor-based reset pulse control, compatibility with battery-powered and automotive power rails, and TSSOP-8 packaging for space-constrained embedded designs.

Technical Context

The TL7700CPWRG4 integrates a temperature-compensated 1.5 V internal reference, fast comparator, timing generator, and npn open-collector output driver. Its SENSE input compares externally divided rail voltage against a stable 500 mV threshold, while hysteresis is set by resistor-controlled input current (2.5 µA typ).

Reset pulse duration is determined by constant-current (15 µA typ) charging of an external CT capacitor, yielding tpo ≈ Ct × 10⁵ seconds - enabling precise power-on reset timing independent of supply ramp rate. The device operates without external biasing across its full 1.8–40 V range, supporting direct connection to unregulated inputs.

Key Specifications

Pinout & Package

TSSOP-8 package (3.00 mm × 4.40 mm body, 0.65 mm pitch), moisture sensitivity level 1, lead finish NiPdAu, RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar supply-voltage supervision applications.

Compared with TL7700CPWRG4, TPS3808G01DBVR offers lower quiescent current but sacrifices adjustability and hysteresis control, while MAX6816EUT+T provides simpler integration for fixed 3.3 V systems but cannot supervise higher or lower rails without additional level-shifting circuitry.

Availability

TL7700CPWRG4 is available at Aetrix Electronics and suitable for industrial control systems, automotive body electronics, FPGA configuration sequencing, and notebook power management requiring stable component supply across extended temperature and voltage ranges.

Supply support for TL7700CPWRG4 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 personal electronics markets.

The TL7700CPWRG4 belongs to TI's legacy bipolar supervisor product line, designed specifically for robust, wide-input-voltage reset control in cost-sensitive and thermally demanding applications where precision and configurability outweigh ultra-low-power requirements.

FAQ

What is the function of the CT pin on the TL7700CPWRG4?

The CT pin on the TL7700CPWRG4 connects to an internal 15 µA constant-current source that charges an external capacitor to determine RESET pulse duration. When the capacitor voltage reaches the internal comparator threshold, the RESET output transitions from low to high. The CT pin must never be driven externally - it is strictly a sink node for timing capacitor discharge control.

Can the TL7700CPWRG4 monitor a 1.8 V supply directly?

Yes, the TL7700CPWRG4 can monitor a 1.8 V supply directly because its minimum operating voltage is 1.8 V and its internal 500 mV sense threshold remains stable across the full supply range. To do so, connect the 1.8 V rail to the SENSE pin through a resistor divider that scales it to ≥500 mV - for example, R1 = 2.7 kΩ and R2 = 1.0 kΩ yields ~500 mV at SENSE when VDD = 1.8 V.

Does the TL7700CPWRG4 require an external pullup resistor on the RESET pin?

Yes, the TL7700CPWRG4 RESET pin is an npn open-collector output and requires an external pullup resistor to the target logic rail (e.g., 3.3 V or 5 V). Typical values range from 4.7 kΩ to 10 kΩ. Without this pullup, the RESET signal cannot go high, preventing proper release of the reset condition in connected microcontrollers or FPGAs.

How is hysteresis configured on the TL7700CPWRG4?

Hysteresis on the TL7700CPWRG4 is configured by connecting a resistor (R1) between the SENSE pin and GND. The internal SENSE input current (2.5 µA typ) flows through R1, generating Vhys = Is × R1. For example, a 100 kΩ R1 yields ~250 mV hysteresis. This ensures the reset releases at a higher voltage than it asserts, preventing oscillation on noisy supply lines.

What is the maximum timing capacitor value supported by the TL7700CPWRG4?

The TL7700CPWRG4 does not specify an absolute maximum CT value, but practical limits arise from leakage, board parasitics, and required pulse duration. Based on tpo ≈ Ct × 10⁵ seconds, a 1 µF capacitor yields ~100 s pulse - far exceeding typical system needs. For standard power-on reset (10–200 ms), CT values between 100 pF and 10 nF are recommended to maintain accuracy and minimize physical size.