Texas Instruments TPS61045DRBR

Overview

TPS61045 from Texas Instruments is a digitally adjustable, high-frequency boost converter IC designed for LCD/OLED bias supply in portable displays. It operates from 1.8 V to 6 V input, delivers up to 28 V output, features true shutdown with 0.1 µA quiescent current, integrates dual MOSFET switches (Q1 input switch, Q2 main switch), and supports digital voltage programming via CTRL pin timing pulses.

For engineers reviewing the TPS61045 datasheet, TPS61045 pinout, TPS61045 application, or TPS61045 equivalent, key selection considerations include its 6-bit DAC-controlled output adjustment (19.6 mV/step), PFM peak-current control architecture, 1 MHz max switching frequency, 375 mA typical current limit, and VSON-8 package thermal performance (R_θJA = 270 °C/W).

Technical Context

The TPS61045 uses pulse-frequency modulation (PFM) with constant peak-current control - turning on Q2 until inductor current reaches 375 mA (typ), then off for ≥400 ns minimum off-time. Regulation relies on feedback comparator comparing FB voltage to 1.233 V internal reference, enabling stable discontinuous conduction mode (DCM) operation across load and input variations.

Its dual-switch architecture separates input isolation (Q1) from power conversion (Q2): Q1 opens during shutdown to fully disconnect VIN from VO, while Q2 handles energy transfer. The 6-bit DAC on DO pin (0–1.233 V range) dynamically adjusts feedback node voltage via external resistor R3, enabling programmable output without changing R1/R2 divider hardware.

Key Specifications

Pinout & Package

TPS61045 is housed in an 8-pin VSON package (DRB variant), 3.00 mm × 3.00 mm body size, with exposed thermal pad connected to PGND for enhanced thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar boost converter applications.

Compared with TPS61045, TPS61042 offers simplified implementation for fixed-voltage use but sacrifices programmability, while MAX17065 enables higher-frequency operation and tighter integration at the cost of non-compatible control and layout redesign.

Availability

TPS61045 is available at Aetrix Electronics and suitable for LCD bias supply, OLED power management, and handheld device power sequencing requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TPS61045 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 portable power solutions.

The TPS6104x family was engineered specifically for compact, battery-powered display bias applications - emphasizing low quiescent current, digital programmability, and robust shutdown behavior in space-constrained consumer and industrial devices.

FAQ

What is the minimum input voltage required for TPS61045 to regulate a 18-V output?

The TPS61045 requires a minimum input voltage of 1.8 V to operate, but successful regulation at 18 V output depends on load current and inductor selection. At 10 mA load with 4.7 µH inductor, stable regulation is confirmed down to 2.4 V input per typical application data; below that, duty cycle approaches 100% and may trigger UVLO (1.5 V threshold) or reduce efficiency significantly. Always verify with actual board testing under worst-case temperature and tolerance conditions for your TPS61045 design.

How does the CTRL pin timing affect output voltage adjustment on TPS61045?

The CTRL pin on TPS61045 accepts logic pulses to increment or decrement the internal 6-bit DAC: a 1–60 µs low pulse increases DO voltage by one 19.6 mV step, a 140–240 µs low pulse decreases it by one step, and ≥560 µs disables the device. Each step alters the effective feedback divider ratio, shifting output voltage predictably - e.g., with R1=2.2 MΩ, R2=180 kΩ, R3=390 kΩ, one step changes VO by ~0.35 V. Pulses must be separated by ≥1 µs high time (td1) for reliable decoding by the TPS61045 internal state machine.

Can TPS61045 drive a 20-mA load at 22 V output?

The TPS61045 is characterized for 10 mA at 18 V in the datasheet, but its 375 mA peak switch current allows higher output power depending on VIN and efficiency. At VIN = 3.6 V and VO = 22 V, theoretical max continuous output current is ~6.5 mA (assuming 75% efficiency); exceeding this risks entering continuous conduction mode, reducing regulation accuracy and increasing thermal stress. For 20 mA, consider parallel TPS61045 units or a higher-current alternative like TPS61088 - do not assume linear scalability beyond datasheet conditions for your TPS61045 implementation.

What is the role of the exposed thermal pad on the TPS61045 VSON package?

The exposed thermal pad on the TPS61045 DRB package is electrically connected to PGND and serves as the primary thermal conduction path from the die to the PCB. Per TI's layout guidelines, it must be soldered to a dedicated PGND copper pour with ≥4 thermal vias (0.3 mm diameter) to an inner ground plane. Failure to properly connect this pad results in junction temperature rise exceeding the 125°C max operating limit - measured R_θJA degrades from 270 °C/W to >350 °C/W, risking thermal shutdown or long-term reliability loss in sustained 10 mA operation. This pad is not optional for any functional TPS61045 design.

Does TPS61045 require an external Schottky diode, and what are the key selection criteria?

Yes, TPS61045 requires an external Schottky diode (e.g., MBR0530 shown in typical schematic) connected between SW and VO. Key selection criteria include: forward voltage ≤0.4 V at 10 mA (to minimize conduction loss), reverse leakage <1 µA at 30 V (to prevent output droop during shutdown), and fast recovery (<10 ns) to handle 1 MHz switching. Diode capacitance must be minimized (<100 pF) to avoid resonance with output capacitor; TI recommends Zetex ZHZS400 or Vishay SS12 as validated alternatives. Omitting or misselecting the diode causes efficiency collapse and potential TPS61045 instability.