Texas Instruments TPS62745DSST

Overview

TPS62745DSST from Texas Instruments is an ultra-low-quiescent-current synchronous step-down converter optimized for low-power wireless systems powered by dual Li-ion, Li-primary (e.g., Li-SOCl₂), or 4–6-cell alkaline batteries. It delivers up to 300 mA output current at 1.8–3.3 V with 400 nA typical IQ, RF-friendly DCS-Control™ topology, and integrated input voltage switch for ADC scaling.

For engineers reviewing the TPS62745DSST datasheet, TPS62745DSST pinout, TPS62745DSST application, or TPS62745DSST equivalent, key selection criteria include sub-µA quiescent current under light load, 16-step programmable VOUT via VSEL pins, open-drain power-good signaling, integrated VOUT discharge, and operation across 3.3–10 V input with WSON-12 package constraints.

Technical Context

The TPS62745DSST implements TI's DCS-Control™ topology-combining hysteretic and voltage-mode control-to achieve seamless PFM/PWM transition, <2.5% output voltage accuracy over temperature, and fast transient response without external compensation. Its AC loop directly senses VOUT for immediate switching frequency adjustment, while the DC feedback loop ensures stable regulation with low-ESR ceramic capacitors.

It integrates four functional blocks critical for ultra-low-power operation: a 400-nA quiescent current bias network, a digitally controlled VSEL interface selecting 16 discrete output voltages (1.8–3.3 V in 100-mV steps), an EN_VIN_SW–controlled internal MOSFET switch (R_DS(ON) = 85–160 Ω) for input voltage scaling, and a dedicated VOUT discharge path activated during shutdown or UVLO.

Key Specifications

Pinout & Package

TPS62745DSST is housed in a 12-pin WSON package (3 mm × 2 mm) with exposed thermal pad connected to GND. Pin functions are validated per TI SLVSC68A datasheet Rev A (June 2015).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with TPS62745DSST, TPS62746DSST offers tighter VOUT range and marginally lower IQ but identical feature set, while TPS62840DRLR achieves lower IQ at the cost of missing key integration features-making TPS62745DSST optimal for RF-sensitive, battery-constrained designs requiring full functional integration.

Availability

TPS62745DSST is available at Aetrix Electronics and suitable for Bluetooth Low Energy sensor nodes, industrial utility meters, energy harvesting systems, and wireless industrial sensors requiring stable component supply across long-lifecycle deployments.

Supply support for TPS62745DSST 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 designing analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The TPS62745DSST belongs to TI's ultra-low-power DC/DC converter product line, engineered specifically for battery-operated wireless sensing and edge-node applications demanding multi-year runtime and RF coexistence.

FAQ

What is the minimum input voltage required for TPS62745DSST to regulate output?

The TPS62745DSST requires VIN ≥ VOUT + 0.7 V for regulation, with absolute minimum input of 3.3 V. For example, at VOUT = 1.8 V, minimum VIN is 2.5 V-but the device enforces 3.3 V minimum per datasheet specification. Below 3.3 V, undervoltage lockout (UVLO) disables operation; VTH_UVLO− is 2.9 V typical, ensuring clean startup and shutdown behavior. This protects downstream circuitry from unstable regulation during battery depletion.

How does the TPS62745DSST achieve 400 nA quiescent current?

The TPS62745DSST achieves 400 nA typical IQ through a combination of deep-sleep PFM mode, where most internal circuits-including gate drivers and error amplifiers-are powered down between switching pulses, and a highly optimized bias network with low-leakage CMOS design. During light-load PFM operation, the device generates single switching pulses to recharge COUT, then enters extended sleep periods proportional to load current. The 400 nA figure is measured at VIN = 6 V, VOUT = 2 V, IOUT = 0 µA, TJ = 25°C.

Can the output voltage of TPS62745DSST be changed dynamically during operation?

Yes, the TPS62745DSST supports dynamic VOUT scaling during operation via its VSEL1–VSEL4 pins. Changing the binary code reprograms the internal feedback divider, causing VOUT to slew to the new target voltage at a controlled rate defined in the datasheet (typically ~100 mV/ms). This enables adaptive power management-for example, raising VOUT to 3.3 V for RF transmit and lowering to 1.8 V for MCU sleep-without requiring external components or firmware reboot.

What is the purpose of the EN_VIN_SW pin on the TPS62745DSST?

The EN_VIN_SW pin controls an internal MOSFET switch connecting VIN to the VIN_SW terminal. When EN_VIN_SW = High, the switch closes, allowing VIN_SW to source up to 5 mA for external voltage dividers-enabling accurate ADC measurement of input voltage without continuous loading. When EN_VIN_SW = Low, the switch opens, eliminating leakage and preserving battery life. If unused, EN_VIN_SW must be tied to GND to prevent floating.

Does the TPS62745DSST include protection against output short-circuit conditions?

Yes, the TPS62745DSST integrates cycle-by-cycle current limiting on both high-side and low-side MOSFETs. The high-side current limit is typically 480–720 mA, and the low-side limit is 600 mA. During overload or short-circuit, the device reduces switching frequency and limits peak inductor current to prevent thermal damage. Additionally, it features undervoltage lockout (UVLO), thermal shutdown, and integrated VOUT discharge to ensure safe fault recovery-no external protection circuitry is required.