Texas Instruments TL7757CDR

Overview

TL7757CDR from Texas Instruments is a supply-voltage supervisor and precision voltage detector designed for microcomputer and microprocessor systems. It monitors V_CC for undervoltage conditions, asserts active-low RESET below 4.55 V ±120 mV threshold, features 20 µA standby current, and guarantees defined RESET output down to V_CC = 1 V - enabling reliable power-on reset in embedded control and industrial MCU applications.

For engineers reviewing the TL7757CDR datasheet, TL7757CDR pinout, TL7757CDR application, or TL7757CDR equivalent, this page delivers verified technical context, SOIC-8 package mapping, real-world timing behavior (t_PHL/t_PLH ≤ 5 µs), hysteresis-stabilized detection (40–60 mV), and direct alternatives for 4.55 V reset supervision with industrial temperature range compatibility.

Technical Context

The TL7757CDR implements a comparator-based voltage detection architecture with internal precision resistor divider and hysteresis circuitry to prevent oscillatory resets during slow V_CC transitions. Its RESET output is open-drain with 20 mA sink capability and remains valid across 1 V to 7 V supply range.

It generates automatic power-on reset when V_CC rises above ~1 V and holds RESET active until V_CC exceeds the negative-going threshold (V_IT− = 4.55 V ±120 mV) and remains above it by hysteresis margin - ensuring deterministic initialization of digital logic before stable operation.

Key Specifications

Pinout & Package

TL7757CDR is housed in an 8-pin SOIC (D) package per JEDEC MS-012 variation AA, with 1.27 mm pitch, 3.91 mm body width, and 1.75 mm max height. Pin 1 is located at top-left corner with notch or beveled edge marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL7757CDR, TPS3808G33DBVR serves 3.3 V systems with superior quiescent current but cannot replace 4.55 V supervision; MAX691CPA+ offers watchdog extension and tighter long-term stability but requires PCB redesign due to 16-pin DIP form factor and different pinout.

Availability

TL7757CDR is available at Aetrix Electronics and suitable for industrial control, automotive body electronics, and medical device applications requiring stable component supply, long-lifecycle support, and consistent SOIC-8 sourcing.

Supply support for TL7757CDR 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 consumer markets since 1930.

The TL77xx series was developed specifically for cost-sensitive, high-reliability microprocessor reset supervision in commercial-temperature embedded systems - emphasizing precision threshold accuracy, low power, and SOIC-8 manufacturability.

FAQ

What is the exact reset threshold voltage of TL7757CDR and how tightly is it specified?

The TL7757CDR has a nominal negative-going input threshold voltage (V_IT−) of 4.55 V, with a guaranteed range of 4.4 V to 4.7 V over 0°C to 70°C. This ±120 mV tolerance is factory-trimmed and applies across full operating temperature and supply range - making TL7757CDR suitable for 5 V systems requiring robust undervoltage detection without external calibration.

Does TL7757CDR require an external pull-up resistor on the RESET pin?

Yes, TL7757CDR features an open-drain RESET output and requires an external pull-up resistor to V_CC or another logic rail. The datasheet specifies 20 mA sink capability, so a typical 4.7 kΩ pull-up to 5 V yields ~1 mA current - sufficient for driving multiple CMOS inputs while maintaining fast rise time and noise immunity.

Can TL7757CDR operate reliably at VCC = 1.2 V, and what happens to RESET at that level?

Yes - TL7757CDR guarantees defined RESET output behavior down to V_CC = 1 V. At V_CC = 1.2 V, the RESET pin remains actively driven low (as long as V_CC is below the 4.55 V threshold), enabling early fault detection before digital logic becomes operational. This behavior is explicitly tested and specified in the "Power-up reset voltage" parameter (V_res ≤ 1.2 V).

What is the maximum recommended supply voltage for TL7757CDR, and what protection exists above that?

The absolute maximum supply voltage for TL7757CDR is 20 V, but the recommended operating range is 1 V to 7 V. Operation above 7 V is outside specification and may cause parametric shift or accelerated aging. No internal overvoltage protection circuitry is provided - external clamping (e.g., TVS diode) is required if transient overvoltage exposure is expected in the application.

Is TL7757CDR pin-compatible with other members of the TL77xx family, such as TL7705 or TL7709?

No - TL7757CDR is not pin-compatible with TL7705 (5 V threshold, 8-pin SOIC) or TL7709 (9 V threshold, 8-pin SOIC) because all three share identical SOIC-8 pinout (RESET, V_CC, NC, GND, NC, NC, NC, NC). However, TL7757CDR is functionally and physically pin-compatible with TL7705CDR and TL7709CDR within the same package variant, enabling direct substitution when threshold voltage matches design requirements.