Diodes Incorporated PT7M7809JTEX

Overview

PT7M7809JTEX from Diodes Incorporated is a precision 4.00V microprocessor supervisory circuit with push-pull active-low RESET output, 200ms reset pulse width, and guaranteed operation down to VCC = 1.0V. It monitors power supply integrity during power-up, brownout, and power-down in embedded μP systems and provides reliable reset assertion for industrial controllers and network edge devices.

For engineers reviewing the PT7M7809JTEX datasheet, PT7M7809JTEX pinout, PT7M7809JTEX application, or PT7M7809JTEX equivalent, this device delivers deterministic reset timing, low-quiescent-current supervision (10–30µA), and CMOS-compatible manual-reset input-critical for BOM-stable designs in server storage and security system power management.

Technical Context

The PT7M7809JTEX implements a voltage-monitoring comparator with ±2.5% threshold accuracy over –40°C to +85°C, triggering a fixed 200ms (min 140ms, max 400ms) reset pulse upon VCC crossing the 4.00V nominal threshold. Its internal timebase ensures consistent reset release timing independent of supply ramp rate.

No watchdog or manual-reset functionality is integrated in this variant (per Function Comparison Table: Part No. 2), distinguishing it from PT7M7811/7823-series parts. The device operates across 1.0V–5.5V supply range and guarantees RESET validity at VCC ≥ 1.0V, enabling robust low-voltage system initialization.

Key Specifications

Pinout & Package

PT7M7809JTEX is housed in a 3-pin SOT23 (T) plastic package with gull-wing leads, optimized for high-density PCB assembly and thermal performance in space-constrained applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with PT7M7809JTEX, APX809S-40SA-7 offers identical threshold but requires external biasing, while TPS3809K33DBVR targets lower-voltage rails and cannot supervise 4.00V thresholds-making PT7M7809JTEX the sole fit for 5V μP reset with push-pull drive and guaranteed 1.0V operation.

Availability

PT7M7809JTEX is available at Aetrix Electronics and suitable for industrial PLC controllers, network edge routers, and server storage modules requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for PT7M7809JTEX 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial and computing markets.

The PT7M78xx family is designed specifically for microprocessor power-supply supervision-reducing component count and improving system-level reliability in embedded μP systems, networking infrastructure, and security hardware.

FAQ

Does PT7M7809JTEX include a watchdog timer or manual reset input?

No. Per the Function Comparison Table (Part No. 2), PT7M7809JTEX has no watchdog input (WDI) or manual reset (MR) capability. It provides only voltage monitoring and reset generation. Devices like PT7M7823 or PT7M7811 add those features, but PT7M7809JTEX is a dedicated 4.00V supervisor with push-pull RESET output.

What is the minimum supply voltage at which RESET remains valid?

RESET is guaranteed functional down to VCC = 1.0V, per the "Guaranteed RESET/RESET valid at VCC=1.0V" feature and DC Electrical Characteristics table. At 1.0V, RESET output low voltage is specified ≤0.3V with 100µA sink current, ensuring reliable logic-low assertion even during deep brownout.

Can PT7M7809JTEX be used with a 3.3V microprocessor?

No-it is not recommended. PT7M7809JTEX has a 4.00V reset threshold, intended for monitoring 5V rails. Using it on a 3.3V system would cause continuous reset assertion since VCC never reaches 4.00V. For 3.3V supervision, select PT7M7803 (2.63V) or PT7M7810 (3.08V), both in the same family and package.

Is PT7M7809JTEX pin-compatible with other PT7M78xx variants in SOT23?

Yes, for the 3-pin SOT23 (T) package variants-PT7M7803XTEX, PT7M7809XTEX, and PT7M7810XTEX share identical pinout (VCC, GND, RESET). However, function differs: PT7M7803 has open-drain RESET, while PT7M7809/7810 use push-pull. Board-level compatibility requires verifying RESET load requirements and threshold match.