Texas Instruments TL7757CLP

Overview

TL7757CLP from Texas Instruments is a supply-voltage supervisor and precision voltage detector designed for microcomputer and microprocessor systems. It monitors VCC for undervoltage conditions, asserts active-low RESET below 4.55 V ±120 mV threshold, delivers 20 mA sink capability, operates down to 1 V supply, and draws only 20 µA standby current - enabling reliable power-on reset generation in embedded control applications.

For engineers reviewing the TL7757CLP datasheet, TL7757CLP pinout, TL7757CLP application, or TL7757CLP equivalent, this page provides verified technical context, TO-92 package mapping, threshold hysteresis behavior, reset timing characteristics, and validated alternative options for industrial and automotive-grade supervisory circuits.

Technical Context

The TL7757CLP implements an internal comparator-based detection circuit with built-in hysteresis (30–70 mV) to prevent erratic resets during marginal supply transitions. Its RESET output remains active low until VCC exceeds the rising threshold (VIT+ ≈ 4.55 V + hysteresis), and it guarantees defined operation even when VCC rises above 1 V.

It features a fixed 4.55 V detection threshold with ±120 mV tolerance over 0°C to 70°C, supports supply voltages from 1 V to 7 V, and delivers propagation delays under 5 µs (tPLH/tPHL) with 0.05–1 µs rise/fall times - optimized for deterministic reset assertion in cost-sensitive 5 V systems.

Key Specifications

Pinout & Package

TL7757CLP uses the TO-92 (LP) package - a 3-pin through-hole plastic transistor outline with straight leads, 5.34 mm max height, and GND-connected tab. Pin 1 = GND, Pin 2 = VCC, Pin 3 = RESET (open-drain active-low output).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with TL7757CLP, TL7705CP offers higher threshold precision for nominal 5 V rails but lacks the 1 V startup guarantee, while TPS3808G01DBVR enables programmability and nanoamp operation at the cost of added BOM complexity and different footprint.

Availability

TL7757CLP is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, and consumer set-top boxes requiring stable component supply with long-term lifecycle assurance.

Supply support for TL7757CLP 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 digital signal technologies, with decades of expertise in power management and system supervision ICs.

The TL77xx family was developed specifically for cost-sensitive, high-reliability voltage monitoring in microcontroller-based systems - emphasizing precision thresholds, low quiescent power, and robust reset timing in legacy through-hole packages.

FAQ

What is the exact reset threshold voltage of TL7757CLP and how does temperature affect it?

The TL7757CLP has a nominal negative-going input threshold voltage (VIT−) of 4.55 V with ±120 mV tolerance over 0°C to 70°C. At 25°C, typical VIT− is 4.55 V (range 4.43–4.67 V); over full temperature range, min/max is 4.4 V / 4.7 V. The device includes built-in hysteresis (30–70 mV) to maintain stable reset assertion despite thermal drift or supply noise - ensuring TL7757CLP remains within specification across its rated operating environment.

Does TL7757CLP require an external pull-up resistor on the RESET pin?

Yes, TL7757CLP features an open-drain RESET output and requires an external pull-up resistor to the system's logic supply (e.g., 3.3 V or 5 V). Typical values range from 4.7 kΩ to 10 kΩ. This configuration allows wired-OR reset combining and ensures proper logic-level compatibility. The TL7757CLP itself sinks up to 20 mA, so the pull-up must be sized to limit current while maintaining valid high-level voltage - confirming TL7757CLP's interface integrity in mixed-voltage systems.

Can TL7757CLP operate reliably during power-up when VCC rises slowly?

Yes, TL7757CLP guarantees defined RESET behavior once VCC exceeds 1 V, and its propagation delay remains under 5 µs even with VCC slew rates ≤5 V/µs. The internal circuitry activates early in the ramp, and hysteresis (30–70 mV) prevents chatter during slow or noisy transitions. Test data (Figure 11) confirms clean reset pulse generation with VCC rise times as low as microseconds - making TL7757CLP suitable for systems with unregulated inputs or soft-start power supplies where TL7757CLP maintains deterministic supervision.

What is the maximum supply voltage TL7757CLP can withstand without damage?

The absolute maximum supply voltage for TL7757CLP is 20 V, as specified in the Absolute Maximum Ratings table. However, recommended operating conditions limit VCC to 7 V maximum for functional reliability. Operating continuously above 7 V risks parametric shift or accelerated aging, though short transients up to 20 V are survivable. For sustained 12 V rail monitoring, a resistive divider or dedicated high-voltage supervisor is required - TL7757CLP is optimized for 5 V systems and must not be directly connected to >7 V supplies in normal operation.

Is TL7757CLP pin-compatible with other members of the TL77xx family in TO-92 packaging?

Yes, all TL77xx variants in TO-92 (LP) packaging - including TL7757CLP, TL7705CLP, and TL7701CLP - share identical pinout: Pin 1 = GND, Pin 2 = VCC, Pin 3 = RESET. This allows direct substitution within the same temperature grade (C-suffix = 0°C to 70°C) without PCB changes. However, threshold voltages differ (e.g., TL7705CLP = 5.0 V, TL7701CLP = 1.0 V), so functional equivalence requires verification of trip-point alignment - TL7757CLP's 4.55 V threshold is unique to its part number and cannot be assumed across the family.