Texas Instruments LM2795BL/NOPB

Overview

LM2795BL/NOPB from Texas Instruments is a current-regulated switched-capacitor white LED driver IC with four matched constant-current outputs, ±0.5% output current matching, 325–675 kHz switching frequency, and analog/PWM brightness control. It operates from 2.7V to 5.5V input and delivers up to 20 mA per channel for backlighting in single-cell Li-ion portable devices.

For engineers reviewing the LM2795BL/NOPB datasheet, LM2795BL/NOPB pinout, LM2795BL/NOPB application, or LM2795BL/NOPB equivalent, this page provides verified technical context, DSBGA-14 pin mapping, real-world headroom voltage constraints, charge-pump mode transition behavior at 4.7 V, and validated alternative options for LED backlight systems requiring stable current regulation without inductors.

Technical Context

The LM2795BL/NOPB implements a 1.5×/1× fractional CMOS charge pump with automatic pass-mode transition at ~4.7 V input, enabling efficient operation across the full 2.7–5.5 V Li-ion battery range. Its internal current mirror uses a 10:1 ratio referenced to RSET, delivering tightly matched output currents (±0.5%) across D1–D4 terminals.

Brightness is controlled via dual independent paths: linear analog modulation (0–3.0 V on BRGT) and active-high PWM dimming (SD pin), where high logic shuts down the device with 2.3 µA typical quiescent current. The POUT rail provides unregulated 1.5×VIN output usable for auxiliary LED strings or bias rails, subject to ROUT = 3.0 Ω (typ.) droop.

Key Specifications

Pinout & Package

LM2795BL/NOPB is housed in a thin DSBGA package measuring 2.08 mm × 2.403 mm × 0.600 mm, optimized for space-constrained portable PCBs. Pin numbering follows JEDEC-standard bottom-view layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LED driver applications.

Compared with LM2794BL/NOPB, LM2795BL/NOPB offers native compatibility with standard CMOS high-asserted enable signals and open-drain drivers, while TPS61160DRVR trades capacitor-only simplicity for higher output voltage flexibility and greater peak current capacity at the cost of inductor integration and reduced dimming interface options.

Availability

LM2795BL/NOPB is available at Aetrix Electronics and suitable for white LED backlighting, keypad illumination, and portable Li-ion-powered display systems requiring stable, matched current regulation without inductors.

Supply support for LM2795BL/NOPB 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 over 50 years of innovation in precision analog ICs.

The LM2795BL/NOPB belongs to TI's LED lighting driver product line, engineered specifically for compact, high-efficiency backlight solutions in battery-powered consumer and industrial handheld devices.

FAQ

What is the shutdown behavior of the LM2795BL/NOPB?

The LM2795BL/NOPB features an active-high shutdown pin (SD). When SD is driven HIGH (≥0.8×VIN), the device enters shutdown mode with 2.3 µA typical supply current. An internal pull-up to VIN allows direct connection to open-drain GPIO. During shutdown, all D1–D4 outputs are disabled, POUT drops to near-GND, and the charge pump halts. The LM2795BL/NOPB resumes normal operation within 100 µs after SD falls below 0.2×VIN.

How does the LM2795BL/NOPB set LED current using RSET?

The LM2795BL/NOPB uses an external resistor (RSET) connected from the ISET pin to GND to establish the reference current. Internal circuitry mirrors this current 10× to each D1–D4 output, so I_LED ≈ 10 × (V_REF/RSET). With V_REF ≈ 1.24 V (derived from bandgap), a 124 Ω RSET yields ~10 mA per channel. Table 3 in the datasheet provides exact RSET values for 5–20 mA outputs at various BRGT voltages.

Can the LM2795BL/NOPB drive LEDs with forward voltage above 4.0 V?

No - the LM2795BL/NOPB's regulated D1–D4 outputs require sufficient headroom voltage (V_HR = V_POUT − V_DX) to maintain regulation. At 15 mA, minimum V_HR is ~0.3 V (20 mV/mA × 15 mA). Since V_POUT ≤ 1.5 × V_IN and V_IN ≤ 5.5 V, maximum V_POUT is ~8.25 V. Thus, maximum supported V_DX is ~7.95 V - but practical limit is ~3.8 V due to efficiency drop and thermal constraints at high V_DX. For >4.0 V LEDs, use POUT with external ballast resistors or select an inductive boost driver like TPS61160.

What is the role of the POUT pin on the LM2795BL/NOPB?

The POUT pin delivers the unregulated 1.5×VIN output of the internal charge pump. It can supply auxiliary current beyond the four regulated D1–D4 channels - e.g., driving additional LEDs via series resistors or powering low-noise analog circuitry. Because POUT has ~3.0 Ω output resistance, its voltage sags under load: V_POUT = 1.5×V_IN − I_TOTAL × R_OUT. Designers must verify headroom (V_POUT − V_DX) remains ≥0.3 V at max load to avoid regulation loss in D1–D4.

How does brightness control work on the LM2795BL/NOPB?

The LM2795BL/NOPB supports two independent brightness methods: analog control via the BRGT pin (0–3.0 V input linearly scales LED current) and digital PWM control via the SD pin (HIGH = shutdown, LOW = active). When both are used simultaneously - e.g., BRGT set to 1.5 V for mid-range baseline current and SD pulsed at 1 kHz - perceived brightness is the product of analog gain and PWM duty cycle, enabling fine-grained dimming resolution without flicker.