Texas Instruments UC37136M

Overview

UC37136M from Texas Instruments is a bipolar dual high-/low-side power switch IC designed for industrial load control, featuring two 250-mA NPN output switches rated for 35-V maximum operation, internal 46-V collector-emitter voltage clamping, and user-programmable UVLO delay via external capacitor on CDEL pin. It drives resistive, capacitive, and inductive loads in sensor interface and PLC output modules.

For engineers reviewing the UC37136M datasheet, UC37136M pinout, UC37136M application, or UC37136M equivalent, key selection considerations include configurable high/low-side topology per channel, phase programmability of Switch 2 via IN2/INV2 XOR logic, thermal shutdown at 155°C, current limit at 1.1 A, and SOIC-16 (QSOP) package compatibility with industrial temperature range (0°C to +70°C).

Technical Context

The UC37136M integrates two independent NPN power switches with fully decoupled emitter (HSx) and collector (LSx) terminals, enabling flexible high-side (load-to-GND) or low-side (load-to-VCC) configurations. Each switch features dedicated saturation voltage specification (1.15 V @ 25°C, R_LOAD = 100 Ω) and leakage current ≤5 µA under off-state bias conditions.

Control logic includes CMOS-compatible inputs (IN1, IN2, INV2) with defined thresholds (V_IH ≥ 3.5 V, V_IL ≤ 1.5 V), propagation delay ≤3 µs, and an internal XOR gate determining Switch 2 phase. The UVLO circuit disables outputs until V_CC exceeds 8 V, followed by a programmable turn-on delay set by CDEL charging at 2.5 µA to 4 V threshold.

Key Specifications

Pinout & Package

UC37136M is housed in a 16-pin QSOP (SSOP) package (DBQ drawing), with 0.65-mm lead pitch and RoHS-compliant CU NIPDAU finish (MSL Level-2-260°C-1 year). Pin 1 is located at bottom-left corner when notch faces up.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual high-/low-side switch applications.

Compared with UC37136DP, the UC37136M offers finer-pitch QSOP packaging for higher board density; compared with TPS27082LA, it delivers true dual-channel configurability and inductive-clamp protection at lower cost per switch, but lacks current-sense feedback.

Availability

UC37136M is available at Aetrix Electronics and suitable for industrial sensor interfaces, PLC output modules, and automated test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for UC37136M 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 decades of experience in industrial-grade interface and driver ICs.

The UC37136M belongs to TI's legacy bipolar power switch family, engineered specifically for ruggedized industrial load control where reliability, inductive transient suppression, and flexible topology are critical.

FAQ

What is the maximum continuous output current rating for UC37136M?

The UC37136M provides 250 mA total continuous output current - usable either as 250 mA shared across both switches or as 250 mA per switch individually. This rating applies under specified thermal conditions and is supported by internal current limiting that activates at 1.1 A peak to protect against short circuits. The UC37136M maintains this current capability across its full 0°C to +70°C operating temperature range.

Can UC37136M drive inductive loads without external flyback diodes?

Yes, the UC37136M can drive inductive loads without external flyback diodes due to its internal 46-V Zener clamp across each LSx–HSx pair. This clamp safely dissipates energy from inductive kickback during switch turn-off, limiting collector-emitter voltage to 46 V. While effective for moderate-energy inductors, designers should verify clamp power dissipation margins for high-duty-cycle or high-current inductive loads. The UC37136M datasheet confirms this protection is built-in and does not require external components.

How is the UVLO delay time programmed on UC37136M?

The UVLO delay on UC37136M is programmed using an external capacitor connected to the CDEL pin. After V_CC exceeds the 8-V UVLO threshold, an internal 2.5-µA current source charges the capacitor to a 4-V comparator threshold. Delay time ≈ 1.6 ms per nanofarad (e.g., 0.1 µF yields ~160 ms). The UC37136M CDEL pin also supports external reset by pulling it low, allowing dynamic restart of the delay sequence during system operation.

What is the function of the SD pin on UC37136M?

The SD (Shutdown) pin on UC37136M is an open-collector output that sinks up to 8 mA when the device detects overcurrent or during the CDEL delay period. It remains high-impedance otherwise. This pin enables direct connection to an LED (with pull-up resistor) for visual fault indication or to a microcontroller GPIO for interrupt-driven diagnostics. The UC37136M SD signal asserts immediately upon current-limit activation or thermal shutdown, providing real-time system-level fault visibility.

Does UC37136M support both high-side and low-side switching on the same device?

Yes, UC37136M supports independent high-side and low-side configurations per channel: HS1/LS1 and HS2/LS2 are fully separated emitter/collector terminals. Switch 1 (HS1/LS1) can be wired as high-side while Switch 2 (HS2/LS2) operates as low-side - or any other combination - enabling mixed-topology designs like valve control (high-side) paired with indicator lighting (low-side). This flexibility is explicitly confirmed in the UC37136M datasheet Figure 3 and pin description section.