Texas Instruments TL7770-5IDWG4

Overview

TL7770-5IDWG4 from Texas Instruments is a dual-channel power-supply supervisor IC designed for microcomputer and microprocessor systems requiring precise undervoltage/overvoltage monitoring and SCR-based fault protection. It features 5-V and programmable undervoltage sensing (1.47 V threshold at 2VSU), 2.58 V overvoltage threshold, 250-mA peak SCR drive current, and operates across –40°C to 85°C.

For engineers reviewing the TL7770-5IDWG4 datasheet, TL7770-5IDWG4 pinout, TL7770-5IDWG4 application, or TL7770-5IDWG4 equivalent, this device supports dual independent supply monitoring with true/complementary reset outputs, externally adjustable reset pulse duration, and integrated SCR gate drive for high-reliability industrial power-up sequencing and overvoltage shutdown.

Technical Context

The TL7770-5IDWG4 implements two independent voltage-monitoring channels: Channel 1 monitors a fixed 5-V supply via 1VSU (VIT+ = 4.64 V typ) and Channel 2 supports programmable undervoltage detection at 2VSU (VIT– = 1.50 V typ). Each channel includes hysteresis (15 mV and 5 mV respectively) and feeds into separate time-delay circuits controlled by external capacitors (CT).

Its overvoltage protection uses an internal SCR triggered when VSO exceeds 2.58 V, delivering 250-mA peak current to the SCR DRIVE terminal for driving external high-current SCRs or warning circuits. The device latches RESET/RESET outputs until VSU recovers above threshold for the programmed delay, ensuring robust system initialization.

Key Specifications

Pinout & Package

TL7770-5IDWG4 is housed in a 16-pin SOIC (DW) package with 1.27-mm pitch, 7.5 mm × 10.3 mm body, and maximum height of 2.65 mm - compatible with standard surface-mount assembly and reflow profiles (MSL Level-1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply supervisor applications.

Compared with TPS3619-50DBVR and MAX6816ESE+, the TL7770-5IDWG4 uniquely integrates dual independent voltage supervision, programmable timing, and 250-mA SCR drive-enabling single-chip solutions for industrial systems requiring coordinated reset and hardware-level overvoltage cutoff without discrete driver components.

Availability

TL7770-5IDWG4 is available at Aetrix Electronics and suitable for industrial PLCs, telecom line cards, motor drive inverters, and rail-to-rail sensor nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TL7770-5IDWG4 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 leader specializing in analog, embedded processing, and power management technologies, with decades of experience in high-reliability industrial and automotive ICs.

The TL7770 family was engineered specifically for robust power-supply supervision in microcomputer systems-emphasizing dual-rail monitoring, SCR-based overvoltage protection, and wide-temperature operation for mission-critical industrial control.

FAQ

What is the function of the 1SCR DRIVE and 2SCR DRIVE pins on the TL7770-5IDWG4?

The 1SCR DRIVE and 2SCR DRIVE pins on the TL7770-5IDWG4 deliver up to 250-mA peak current to trigger external silicon-controlled rectifiers during overvoltage events. Each pin corresponds to its respective VSO input (1VSO or 2VSO) and provides 25-mA continuous drive capability. This allows the TL7770-5IDWG4 to directly control high-current SCRs for hardware-level power cutoff without additional driver circuitry, making it ideal for fail-safe industrial protection schemes.

How does the TL7770-5IDWG4 generate reset pulses during power-up?

The TL7770-5IDWG4 asserts RESET/RESET outputs when VCC exceeds 1 V, then latches them active once VCC reaches 3.5 V. The duration of the active state is determined by an external timing capacitor (CT) connected to the 1CT or 2CT pin, with td ≈ 20×10³ × C seconds. This ensures the microcontroller receives a clean, extended reset pulse even with slow-ramping or noisy power supplies-critical for reliable boot in industrial environments.

Can the TL7770-5IDWG4 monitor both 5-V and 12-V supplies simultaneously?

Yes-the TL7770-5IDWG4 supports dual independent monitoring: Channel 1 (1VSU) is optimized for 5-V supplies (VIT+ = 4.64 V), while Channel 2 (2VSU) is programmable for lower thresholds (1.50 V typical), allowing indirect monitoring of higher rails like 12-V via resistive dividers. For direct 12-V sensing, the TL7770-12IDWG4 variant is specified-but the TL7770-5IDWG4's flexibility makes it suitable for mixed-rail systems where one channel handles logic voltage and the other supervises auxiliary or battery-backed rails.

What is the purpose of the RESIN inputs on the TL7770-5IDWG4?

The 1RESIN and 2RESIN inputs on the TL7770-5IDWG4 provide manual reset control: pulling either low initiates a full time-delayed reset sequence-even when supply voltages are within specification. This enables system-level reset requests (e.g., from watchdog timers or front-panel buttons) while maintaining the same timing and output behavior as power-on reset. Each RESIN input is independently buffered and compatible with TTL/CMOS logic levels (VIH ≥ 2 V, VIL ≤ 0.8 V).

Does the TL7770-5IDWG4 require external components to operate?

Yes-the TL7770-5IDWG4 requires external timing capacitors (CT) on 1CT and 2CT pins to set reset pulse duration, and typically uses pull-up resistors on RESIN inputs for noise immunity. For overvoltage detection, external resistive dividers scale high-voltage rails (e.g., 48-V) to fit the 2.58-V VSO threshold. No external reference or regulator is needed: the device integrates a temperature-compensated bandgap reference and operates directly from 3.5–18-V VCC.