Texas Instruments TL7770-12CDWR

Overview

TL7770-12CDWR from Texas Instruments is a dual-channel power-supply supervisor IC designed for microcomputer/microprocessor systems requiring precise 12-V and programmable undervoltage monitoring. It provides true/complementary reset outputs, 250-mA peak SCR gate drive, and externally adjustable reset pulse duration via timing capacitor. Used in industrial power-up sequencing and overvoltage protection circuits.

For engineers reviewing the TL7770-12CDWR datasheet, TL7770-12CDWR pinout, TL7770-12CDWR application, or TL7770-12CDWR equivalent, key selection factors include its dual 12-V/programmable threshold sensing, SCR-triggered overvoltage response, temperature-compensated reference, and SOIC-16 package compatibility with legacy 5-V/12-V system rails.

Technical Context

The TL7770-12CDWR integrates two independent voltage supervisors: Channel 1 monitors fixed 12-V supply (VIT+ = 10.68–11.12 V) at 1VSU, while Channel 2 supports programmable undervoltage detection (VIT– = 1.47–1.53 V) at 2VSU. Both channels feature hysteresis (36 mV and 5 mV respectively) and generate synchronized RESET/RESET outputs upon threshold violation.

Its overvoltage protection uses an internal SCR triggered at VSO = 2.48–2.68 V, delivering 250-mA peak current to external SCR gates. Reset pulse duration (td) is set by external CT capacitor per td ≈ 20 × 10³ × C, enabling precise power-on delay tuning across 0°C to 70°C operation.

Key Specifications

Pinout & Package

TL7770-12CDWR is housed in a 16-pin SOIC (DW) package measuring 10.3 mm × 7.5 mm × 2.65 mm max height, RoHS-compliant with NIPDAU lead finish and MSL Level-1 rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL7770-12CDWR, TPS3619-50DBVR offers simpler integration for basic 5-V systems but lacks dual monitoring and SCR drive; MAX6816ESE+ scales channel count for complex multi-rail designs yet sacrifices overvoltage response and timing flexibility - TL7770-12CDWR remains optimal for 12-V-critical applications requiring hardware-level fault shutdown.

Availability

TL7770-12CDWR is available at Aetrix Electronics and suitable for industrial PLC power sequencing, telecom line card supervision, medical diagnostic equipment, automotive infotainment head units, and embedded computing requiring stable component supply across commercial temperature range.

Supply support for TL7770-12CDWR 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 over 90 years of innovation history.

The TL7770 series was developed specifically for robust power-supply supervision in microcomputer systems, emphasizing dual-rail monitoring, hardware-triggered overvoltage protection, and precise reset timing under variable thermal conditions.

FAQ

What is the minimum VCC voltage required for TL7770-12CDWR to assert RESET?

The TL7770-12CDWR asserts RESET when VCC exceeds 1 V (typical), ensuring early reset activation during power ramp-up before full rail stabilization. This behavior is confirmed in the absolute maximum ratings table and functional description, where RESET becomes active at VCC ≥ 1 V during power-on, providing fail-safe initialization even under slow-rising or brownout conditions. The TL7770-12CDWR maintains this threshold across its 0°C to 70°C operating range.

How does TL7770-12CDWR differ from TL7770-5CDWR in sensing configuration?

The TL7770-12CDWR features a fixed 12-V undervoltage threshold (10.68–11.12 V) at 1VSU, while TL7770-5CDWR uses a fixed 5-V threshold (4.46–4.64 V) at the same pin. Both share identical 2VSU programmability (1.47–1.53 V), SCR drive capability, and timing architecture. The TL7770-12CDWR is optimized for systems where primary rail supervision targets 12-V domains, such as industrial motor drives or telecom power modules.

Can TL7770-12CDWR drive an external SCR directly without additional components?

Yes, TL7770-12CDWR delivers 250-mA peak current and 25-mA continuous current from its SCR DRIVE pins, sufficient to trigger standard high-current SCRs like the C106D or BT169 without external amplification. The datasheet explicitly states this capability applies to both Channel 1 and Channel 2 SCR DRIVE terminals, enabling direct crowbar implementation for overvoltage protection in power supplies and battery management systems.

What timing capacitor value yields a 100-ms reset pulse duration for TL7770-12CDWR?

Using the formula td ≈ 20 × 10³ × C (where td is in seconds and C in farads), a 100-ms pulse requires C = 0.0001 / 20,000 = 5 µF. The TL7770-12CDWR datasheet specifies 10 µF as the maximum recommended CT value, so 5 µF falls within valid operating range and provides reliable 100-ms delay. This calculation is derived directly from the "time-delay function" section and verified in timing diagrams Figure 2a/2b.

Is TL7770-12CDWR pin-compatible with other TL7770 variants in SOIC-16 package?

Yes, all TL7770 variants (including TL7770-5CDWR, TL7770-12CDWR, TL7770-5IDWR) share identical SOIC-16 (DW) pinout and electrical characteristics except for their factory-trimmed VSU thresholds. Pin assignments for RESIN, RESET, VSU, VSO, SCR DRIVE, CT, VCC, and GND are fully consistent across the family, enabling drop-in replacement in designs where threshold requirements align with the selected variant's specification.