Microchip Technology TC1303B-ZS0EUNTR

Overview

TC1303B-ZS0EUNTR 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 at 500 mA and 3.3 V at 300 mA from a 2.7–5.5 V input, features 65 µA typical quiescent current, 2.0 MHz fixed-frequency PWM operation, and operates across –40°C to +125°C junction temperature. It targets space-constrained portable electronics requiring tightly regulated dual supplies.

For engineers reviewing the TC1303B-ZS0EUNTR datasheet, TC1303B-ZS0EUNTR pinout, TC1303B-ZS0EUNTR application, or TC1303B-ZS0EUNTR equivalent, key selection criteria include its LDO-monitored PG function, independent shutdown control for each regulator, internal compensation, 137 mV typical dropout at 200 mA on VOUT2, and compatibility with 1 µF ceramic output capacitors on the LDO rail.

Technical Context

The TC1303B-ZS0EUNTR implements a synchronous buck stage with PFM/PWM auto-transition and an independently controlled LDO stage, both internally compensated. Its PG output is a push-pull signal tied exclusively to VOUT2 regulation status, with 94% threshold high and 89% threshold low relative to VOUT2, plus 300 ms active delay - optimized for processor reset timing in battery-powered systems.

It supports adjustable (0.8–4.5 V) or fixed VOUT1 outputs (e.g., 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V) and fixed VOUT2 outputs (1.5 V, 1.8 V, 2.5 V, 3.3 V); the ZS0EUNTR variant is factory-configured for VOUT1 = 1.8 V and VOUT2 = 3.3 V in a 10-pin 3×3 mm DFN package with exposed thermal pad.

Key Specifications

Pinout & Package

TC1303B-ZS0EUNTR is housed in a thermally enhanced 10-pin 3×3 mm DFN package (EP = exposed pad connected to AGND). The pinout reflects dedicated, non-multiplexed functions with strict separation between buck and LDO control paths.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TC1303C-ZS0EUNTR, TC1303B-ZS0EUNTR simplifies reset sequencing by tying PG solely to VOUT2, reducing dependency on buck startup time; versus TPS62231DRYR, it delivers full dual-rail integration in half the PCB area but trades off input voltage flexibility and peak efficiency at ultra-light loads.

Availability

TC1303B-ZS0EUNTR is available at Aetrix Electronics and suitable for handheld medical instruments, USB-powered devices, and portable computers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for TC1303B-ZS0EUNTR 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, headquartered in Chandler, Arizona.

The TC1303 family was designed specifically for space-constrained, battery-operated applications needing highly integrated, low-quiescent dual-rail power conversion - emphasizing minimal external components, robust thermal performance, and precise power-good timing.

FAQ

What output voltages does the TC1303B-ZS0EUNTR provide?

The TC1303B-ZS0EUNTR is factory-configured with a fixed 1.8 V output on VOUT1 (buck regulator) and a fixed 3.3 V output on VOUT2 (LDO). These values are laser-trimmed during manufacturing and cannot be adjusted externally. Both outputs are internally compensated and require only standard ceramic capacitors for stable operation - no resistive feedback network is needed for the TC1303B-ZS0EUNTR.

How does the power-good (PG) output behave on the TC1303B-ZS0EUNTR?

The TC1303B-ZS0EUNTR features a push-pull PG output that monitors only the LDO output (VOUT2). It asserts high when VOUT2 reaches 94% of its nominal value and deasserts when VOUT2 falls below 89%. A built-in 300 ms delay ensures stable rail establishment before enabling downstream logic. This behavior is distinct from TC1303A (PG monitors buck only) and TC1303C (PG monitors both rails), making the TC1303B-ZS0EUNTR optimal for systems where LDO stability dictates safe operation.

Can the TC1303B-ZS0EUNTR operate from a single Li-ion cell?

Yes - the TC1303B-ZS0EUNTR supports input voltages from 2.7 V to 5.5 V, fully covering the discharge curve of a single Li-ion cell (typically 4.2 V down to ~2.8 V). Its 137 mV typical dropout on VOUT2 enables reliable 3.3 V output even at end-of-discharge, and the 1.8 V buck output maintains regulation with >280 mV headroom at 500 mA. Undervoltage lockout activates at 2.55 V nominal, preventing brownout operation.

What package type and thermal characteristics apply to the TC1303B-ZS0EUNTR?

The TC1303B-ZS0EUNTR uses a 10-pin 3×3 mm DFN package with an exposed thermal pad (EP) that must be soldered to AGND for optimal thermal performance. Its junction-to-ambient thermal resistance (θJA) is 41°C/W on a typical 4-layer board with internal ground plane and two vias under the EP. This allows continuous 500 mA buck output at ambient temperatures up to +85°C without forced airflow - verified per Microchip's DS21949C characterization.

Does the TC1303B-ZS0EUNTR require external compensation components?

No - both the buck regulator and LDO in the TC1303B-ZS0EUNTR are fully internally compensated. This eliminates the need for external compensation capacitors or resistors on either control loop, reducing bill-of-materials cost and PCB area. The design achieves stable operation with only the recommended input and output ceramic capacitors (4.7 µF on VIN, 4.7 µF on VOUT1, 1 µF on VOUT2), as validated in Microchip's typical application circuits for the TC1303B-ZS0EUNTR.