Microchip Technology TC1303B-PF0EUNTR

Overview

TC1303B-PF0EUNTR from Microchip Technology is a dual-output power management IC integrating a 500 mA synchronous buck regulator and a 300 mA low-dropout linear regulator (LDO), with the power-good (PG) output monitoring only the LDO output (VOUT2). It delivers 1.8 V on VOUT1 and 3.3 V on VOUT2, operates from 2.7–5.5 V input, and features 65 µA typical quiescent current and -40°C to +125°C junction temperature range - ideal for portable medical instruments and USB-powered devices requiring tightly regulated dual rails.

For engineers reviewing the TC1303B-PF0EUNTR datasheet, TC1303B-PF0EUNTR pinout, TC1303B-PF0EUNTR application, or TC1303B-PF0EUNTR equivalent, key selection considerations include its LDO-monitored PG function, independent shutdown control for each regulator, 2.0 MHz fixed-frequency PWM operation with automatic PFM transition at light load, and compatibility with 1 µF ceramic output capacitors on both outputs.

Technical Context

The TC1303B-PF0EUNTR implements a synchronous buck converter with internal P-channel and N-channel MOSFETs (R_DS(on) = 450 mΩ each), fixed 2.0 MHz switching frequency under heavy load, and seamless auto-transition to PFM mode below ~10 mA to maintain ultra-low IQ. Its LDO uses a separate input (VIN2), supports 137 mV typical dropout at 200 mA, and is internally compensated for stability with only a 1 µF output capacitor.

Power-good logic is configured as a push-pull output (unlike open-drain variants) and asserts when VOUT2 reaches ≥94% of nominal (e.g., ≥3.102 V for 3.3 V output), with 300 ms delay used for processor reset sequencing. UVLO activates at 2.55 V (typical) with 200 mV hysteresis, and thermal shutdown triggers at 165°C with 10°C hysteresis.

Key Specifications

Pinout & Package

TC1303B-PF0EUNTR is housed in a 10-pin 3×3 mm DFN package with exposed thermal pad (EP), optimized for high-density PCB layouts and thermal performance (θ_JA = 41°C/W on 4-layer board). Pin 11 (EP) must be soldered to AGND for electrical integrity and thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output regulator applications.

Compared with MCP16311-H/MS and TPS65023BRSBR, TC1303B-PF0EUNTR uniquely integrates LDO-monitored push-pull PG in a compact DFN, enabling simpler reset architecture and lower BOM count for dual-rail portable designs - without sacrificing thermal robustness or light-load efficiency.

Availability

TC1303B-PF0EUNTR is available at Aetrix Electronics and suitable for portable medical instruments, USB-C powered peripherals, and handheld diagnostic tools requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for TC1303B-PF0EUNTR 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

Microchip Technology is a leading provider of microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with high-reliability silicon and development tools.

The TC1303 family was designed specifically for space-constrained, battery-powered applications needing dual regulated rails with ultra-low quiescent current, independent control, and integrated power-good monitoring - targeting portable computing and medical instrumentation.

FAQ

What output voltages does the TC1303B-PF0EUNTR provide?

The TC1303B-PF0EUNTR provides fixed 1.8 V on VOUT1 (buck output) and fixed 3.3 V on VOUT2 (LDO output), both with ±0.3% tolerance over temperature and line. These values are factory-set and require no external feedback resistors - VFB1/VOUT1 pin is internally connected to the 1.8 V output node.

How does the power-good (PG) function work on the TC1303B-PF0EUNTR?

The TC1303B-PF0EUNTR features a push-pull PG output that monitors only the LDO output (VOUT2). It asserts high when VOUT2 reaches ≥94% of its nominal value (e.g., ≥3.102 V for 3.3 V), with a built-in 300 ms delay used for reliable processor reset. This differs from TC1303A (PG monitors buck) and TC1303C/TC1304 (PG monitors both).

Can the TC1303B-PF0EUNTR operate from a single Li-ion cell?

Yes - the TC1303B-PF0EUNTR supports an input voltage range of 2.7 V to 5.5 V, fully covering the discharge curve of a standard single-cell Li-ion battery (2.7–4.2 V). Its 137 mV typical LDO dropout at 200 mA ensures the 3.3 V rail remains regulated down to VIN2 = 3.437 V, and UVLO releases at 2.55 V (typical) with hysteresis.

What is the thermal performance of the TC1303B-PF0EUNTR in the DFN package?

In the 10-pin 3×3 mm DFN package with exposed pad (EP), the TC1303B-PF0EUNTR achieves θ_JA = 41°C/W on a typical 4-layer PCB with internal ground plane and two thermal vias under the EP. Thermal shutdown activates at 165°C (typical) with 10°C hysteresis, and the device is rated for continuous operation up to +125°C junction temperature.

Does the TC1303B-PF0EUNTR require external compensation components?

No - both the buck regulator and LDO in the TC1303B-PF0EUNTR are internally compensated. The buck stage stabilizes with a standard 4.7 µH inductor and 4.7 µF input/output ceramic capacitors; the LDO requires only a 1 µF ceramic capacitor on VOUT2. No external RC networks or compensation pins are needed.