Texas Instruments TL7757ILP

Overview

TL7757ILP from Texas Instruments is a precision supply-voltage supervisor IC designed for microcomputer and microprocessor systems. It monitors V_CC for undervoltage conditions, provides a reset output active low at 4.55 V ±120 mV threshold, delivers 20 mA sink capability, and operates across −40°C to +85°C with 20 µA standby current. It is used in industrial control power-up sequencing.

For engineers reviewing the TL7757ILP datasheet, TL7757ILP pinout, TL7757ILP application, or TL7757ILP equivalent, key selection criteria include its TO-92 package compatibility, guaranteed reset assertion below 1.2 V during power-up, hysteresis of 30–70 mV to prevent chatter, and −40°C to +85°C industrial temperature rating.

Technical Context

The TL7757ILP implements a precision bandgap-based voltage detector with comparator hysteresis to ensure stable reset assertion/deassertion. Its internal circuitry generates an active-low RESET signal when V_CC drops below 4.4 V (min) or rises above 4.7 V (max), with propagation delays under 5 µs.

It features a dedicated power-on reset generator that guarantees RESET remains active until V_CC exceeds 1 V, and maintains defined output behavior down to 1 V supply - critical for reliable initialization in brown-out scenarios.

Key Specifications

Pinout & Package

TL7757ILP uses the TO-92 (LP) package: 3-pin, straight or formed leads, 5.34 mm max height, lead material tin (Sn), no moisture sensitivity level (N/A), bulk packaging (1000 pcs).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL7757ILP, TL7705CPK offers tighter threshold tolerance but narrower temperature range and unspecified hysteresis, while TPS3808G12DBVR delivers lower power and wider temp range at the cost of added external components and non-drop-in replacement.

Availability

TL7757ILP is available at Aetrix Electronics and suitable for industrial PLC power sequencing, embedded metering systems, and factory automation sensors requiring stable component supply with long lifecycle support.

Supply support for TL7757ILP 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 TL77xx family was engineered specifically for robust, low-cost supply monitoring in microcontroller-based systems where precision threshold, hysteresis, and guaranteed power-on reset are mandatory.

FAQ

What is the minimum supply voltage at which TL7757ILP guarantees RESET assertion?

The TL7757ILP guarantees RESET output becomes active (low) when V_CC drops below 4.4 V (minimum threshold) and remains asserted until V_CC rises above 4.7 V (maximum threshold), with hysteresis preventing chatter. Additionally, during power-up, RESET is guaranteed active until V_CC exceeds 1.2 V - a critical feature for reliable initialization. This behavior is fully specified across −40°C to +85°C for TL7757ILP.

Does TL7757ILP require an external pull-up resistor on the RESET pin?

Yes, TL7757ILP features an open-drain RESET output and requires an external pull-up resistor to the system's logic supply (typically 3.3 V or 5 V). The device sinks up to 20 mA, so the pull-up value must be selected to ensure sufficient voltage rise time and avoid excessive current draw - e.g., 10 kΩ for 5 V systems yields ~0.5 mA static current. No internal pull-up is present in TL7757ILP.

What is the thermal resistance (θ_JA) of the TL7757ILP in its TO-92 package?

The TL7757ILP in the TO-92 (LP) package has a junction-to-ambient thermal resistance (θ_JA) of 140°C/W, as specified in the Absolute Maximum Ratings table. This value assumes standard PCB mounting with no copper pour; actual thermal performance improves significantly with PCB copper heatsinking. The maximum allowable power dissipation is calculated as P_D = (T_J(max) − T_A) / θ_JA, where T_J(max) = 150°C.

Can TL7757ILP be used with a 3.3 V supply rail?

No - TL7757ILP is not rated for reliable operation on 3.3 V supplies. Its specified reset threshold is 4.55 V ±120 mV, and recommended operating supply range is 1 V to 7 V, but functional reset behavior requires V_CC to reach at least 4.4 V to deassert RESET. Using it on a 3.3 V rail would leave RESET permanently asserted. For 3.3 V systems, consider alternatives like TL7733 or TPS3808G33.

Is TL7757ILP pin-compatible with other members of the TL77xx family in TO-92 packages?

Yes - all TL77xx variants in the TO-92 (LP) package (e.g., TL7757ILP, TL7705CLP, TL7709CLP) share identical pinout: Pin 1 = GND, Pin 2 = V_CC, Pin 3 = RESET (open-drain). This allows direct substitution within the same temperature grade (e.g., TL7757ILP ↔ TL7705ILP) when threshold voltage requirements align, though threshold values and hysteresis specs differ between part numbers.