Texas Instruments TPS61085PWRG4

Overview

TPS61085PWRG4 from Texas Instruments is a high-efficiency, adjustable-frequency step-up DC-DC converter with integrated 2.0-A/0.13-Ω N-channel MOSFET, supporting 2.3 V to 6 V input and up to 18.5 V output. It delivers 12 V at 600 mA in typical applications and features selectable 650 kHz or 1.2 MHz switching for optimized size or efficiency. Used in handheld devices and TFT LCD bias supplies.

For engineers reviewing the TPS61085PWRG4 datasheet, TPS61085PWRG4 pinout, TPS61085PWRG4 application, or TPS61085PWRG4 equivalent, key selection criteria include input voltage range (2.3–6 V), output voltage programmability via FB divider, soft-start control via external capacitor, thermal shutdown (150°C), and frequency-selectable operation for layout flexibility.

Technical Context

The TPS61085PWRG4 operates in current-mode control with quasi-constant frequency and adaptive off-time, enabling fast line and load transient response. Its externally compensated transconductance error amplifier (gm = 107 µA/V) supports stability tuning across wide operating conditions.

It implements undervoltage lockout (UVLO threshold: 2.3 V rising), overvoltage protection on FB (trip at ~1.275 V), and pulse-skipping in light-load DCM mode. Switching frequency is set by FREQ pin logic level - GND for 650 kHz, IN for 1.2 MHz - with typical tolerance ±15%.

Key Specifications

Pinout & Package

TPS61085PWRG4 is housed in an 8-pin VSSOP (DGK) package measuring 3.0 mm × 3.0 mm × 1.1 mm, optimized for space-constrained portable designs. Thermal resistance R_θJA is 189.3°C/W, requiring minimal copper area for standard operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS61085PWRG4, TPS61088RHLR offers higher current capability but requires redesign of compensation and layout, while MAX17062ETA+ sacrifices flexibility for integration and footprint reduction - making TPS61085PWRG4 optimal for mid-power, design-flexible portable systems.

Availability

TPS61085PWRG4 is available at Aetrix Electronics and suitable for handheld devices, GPS receivers, digital still cameras, and TFT LCD bias supplies requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for TPS61085PWRG4 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 ICs, with decades of expertise in high-efficiency DC-DC conversion.

The TPS61085PWRG4 belongs to TI's high-frequency boost converter product line, designed specifically for portable and battery-powered applications demanding compact size, wide input range, and reliable high-voltage output generation.

FAQ

What input voltage range does the TPS61085PWRG4 support?

The TPS61085PWRG4 supports an input voltage range of 2.3 V to 6 V, enabling direct operation from single-cell Li-ion batteries (2.7–4.2 V), two alkaline cells (2.4–3.2 V), or three NiMH cells (3.0–4.2 V). The device incorporates undervoltage lockout that disables operation below 2.3 V (rising) to prevent erratic behavior during brownout conditions.

How is the output voltage set on the TPS61085PWRG4?

The output voltage of the TPS61085PWRG4 is set using an external resistor divider connected to the FB pin. With a precise internal reference of 1.238 V, the output voltage is calculated as V_OUT = 1.238 V × (1 + R1/R2). For example, using R2 = 18.2 kΩ and R1 = 158 kΩ yields a nominal 12 V output. Feedback bias current is only 0.1 µA, minimizing divider error.

Can the TPS61085PWRG4 operate at both 650 kHz and 1.2 MHz?

Yes, the TPS61085PWRG4 supports dual switching frequencies: 650 kHz when the FREQ pin is tied to GND, and 1.2 MHz when FREQ is tied to IN. This selection directly impacts external component sizing - 1.2 MHz allows use of smaller inductors (e.g., 3.3 µH), while 650 kHz improves light-load efficiency and reduces EMI. Frequency tolerance is ±15% over temperature and line.

What protection features does the TPS61085PWRG4 include?

The TPS61085PWRG4 integrates undervoltage lockout (UVLO), thermal shutdown (150°C trip with 14°C hysteresis), overvoltage protection on the FB pin (~1.275 V), and cycle-by-cycle current limiting (2.0 A minimum). These features protect both the IC and downstream circuitry during fault conditions such as shorted outputs, excessive ambient temperature, or input under-voltage.

Is soft-start configurable on the TPS61085PWRG4?

Yes, the TPS61085PWRG4 provides adjustable soft-start via the SS pin. Connecting an external capacitor (e.g., 100 nF) between SS and GND creates a controlled ramp of the internal current limit from 0 A to full scale, preventing inrush current into output capacitors. The SS pin is charged at ~10 µA; larger capacitors extend soft-start time linearly, allowing customization for specific system requirements.