Texas Instruments TPS61085DGKR

Overview

TPS61085DGKR from Texas Instruments is a high-efficiency, current-mode boost 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 features selectable 650 kHz or 1.2 MHz switching frequency, adjustable soft-start via external capacitor, and operates in CCM/DCM/pulse-skipping modes for portable TFT LCD bias, GPS receivers, and DSL modems.

For engineers reviewing the TPS61085DGKR datasheet, TPS61085DGKR pinout, TPS61085DGKR application, or TPS61085DGKR equivalent, key selection considerations include input voltage range (2.3–6 V), peak switch current limit (2.0 A min), feedback regulation voltage (1.238 V), thermal shutdown threshold (150 °C), and VSSOP-8 package compatibility with space-constrained handheld designs.

Technical Context

The TPS61085DGKR implements adaptive off-time current-mode control with external compensation, enabling stable operation across wide load and line variations. Its quasi-constant frequency architecture supports both continuous conduction mode (CCM) above half-inductor ripple current and discontinuous conduction mode (DCM) at light loads, with pulse skipping below ~10 mA to maintain regulation.

Switching frequency is selected via FREQ pin logic level: GND sets 650 kHz (higher efficiency, larger inductors), while IN sets 1.2 MHz (faster transient response, smaller passives). The COMP pin interfaces with an external RC network to tune loop bandwidth and phase margin-standard values are R_COMP = 47 kΩ and C_COMP = 1.6 nF for 12 V output at 3.3 V input and 1.2 MHz.

Key Specifications

Pinout & Package

TPS61085DGKR is housed in an 8-pin VSSOP (DGK) package measuring 3.00 mm × 3.00 mm × 1.10 mm, optimized for high-density portable PCBs. Thermal resistance R_θJA is 189.3 °C/W, requiring minimal copper area for thermal relief in handheld applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS61085DGKR, TPS61088RHLR delivers higher current and lower input voltage support but demands more PCB area and redesign of compensation; MAX17062ETA+ simplifies layout with integrated soft-start but sacrifices frequency flexibility and loop tuning capability.

Availability

TPS61085DGKR is available at Aetrix Electronics and suitable for handheld devices, GPS receivers, digital still cameras, and DSL modems requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for TPS61085DGKR 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 and automotive-grade reliability.

The TPS61085DGKR belongs to TI's high-frequency boost converter product line, designed specifically for space-constrained portable electronics requiring regulated high-voltage rails from single-cell batteries or low-voltage system supplies.

FAQ

What is the minimum input voltage required for TPS61085DGKR to operate?

The TPS61085DGKR has a guaranteed minimum operating input voltage of 2.3 V under recommended conditions. Below this threshold, undervoltage lockout (UVLO) disables the device to prevent erratic behavior. The UVLO rising threshold is 2.3 V, and the falling threshold is 2.2 V, providing 100 mV hysteresis. This makes TPS61085DGKR suitable for single-cell Li-ion (2.7–4.2 V), NiMH (2.4–3.0 V), or alkaline (2.4–3.2 V) battery inputs.

How does the FREQ pin affect switching frequency and efficiency in TPS61085DGKR?

The FREQ pin on the TPS61085DGKR selects between two fixed switching frequencies: grounding FREQ sets 650 kHz, while connecting it to IN sets 1.2 MHz. At 650 kHz, the converter achieves higher peak efficiency (up to 94% at medium loads) due to lower switching losses, but requires larger inductors (e.g., 6.8 µH). At 1.2 MHz, efficiency drops ~2–3% but enables smaller passives and faster load transient response - critical for TPS61085DGKR applications like GPS front-ends.

Can TPS61085DGKR drive a 12 V, 600 mA load from a 3.3 V input?

Yes, the TPS61085DGKR is explicitly validated for 3.3 V to 12 V conversion at up to 600 mA output current, as shown in the TI datasheet Figure 8 and Table 2. With 1.2 MHz operation, a 3.3 µH inductor, and proper compensation (e.g., R_COMP = 47 kΩ, C_COMP = 1.6 nF), TPS61085DGKR maintains regulation and <1% output ripple under full load. Peak switch current remains within the 2.0-A minimum limit, even at 3.3 V_IN min.

What is the purpose of the COMP pin on TPS61085DGKR, and how is it configured?

The COMP pin on TPS61085DGKR is the output of the internal transconductance error amplifier and serves as the control node for loop compensation. It must be connected to an external RC network (e.g., 47 kΩ resistor and 1.6 nF capacitor to GND) to stabilize the feedback loop. This configuration sets dominant pole and zero locations, ensuring phase margin >45° and minimizing output voltage overshoot during load steps - a critical design step for reliable TPS61085DGKR deployment.

Does TPS61085DGKR include thermal protection, and how does it behave?

Yes, TPS61085DGKR integrates thermal shutdown with a nominal trigger point of 150 °C junction temperature and 14 °C hysteresis. When triggered, the device halts switching immediately and holds shutdown until the die cools to ~136 °C, at which point normal operation resumes automatically. This protection is independent of input voltage or load and prevents permanent damage during sustained overload, poor heatsinking, or ambient temperature excursions - a key reliability feature for TPS61085DGKR in sealed handheld enclosures.