Analog Devices Inc. LTC3265IDHC#PBF

Overview

LTC3265IDHC#PBF from Analog Devices (formerly Linear Technology) is a low-noise dual-polarity power supply IC integrating a boost charge pump, inverting charge pump, and two post-regulating LDOs - delivering ±15V outputs from a single 12V input. It supports up to 50mA per LDO, operates with ceramic capacitors only, and features programmable 50kHz–500kHz switching frequency and 135µA quiescent current in Burst Mode® with both LDOs active.

For engineers reviewing the LTC3265IDHC#PBF datasheet, LTC3265IDHC#PBF pinout, LTC3265IDHC#PBF application, or LTC3265IDHC#PBF equivalent, key selection considerations include bipolar output noise performance (100µVRMS), VIN_P (4.5–16V) and VIN_N (4.5–32V) input flexibility, MODE/EN+/EN– control logic, thermal protection, and DFN-18 package compatibility with high-density PCB layouts.

Technical Context

The LTC3265IDHC#PBF implements a two-stage architecture: first, switched-capacitor charge pumps generate intermediate rails (VOUT+ = 2•VIN_P or 0.94•2•VIN_P; VOUT– = –VIN_N or –0.94•VIN_N), then low-noise LDOs regulate those rails to precise ±1.2V-referenced outputs. Its dual-mode operation (Burst Mode® for ultra-low IQ vs constant-frequency for lower ripple) is controlled via the MODE pin and externally programmed oscillator frequency via RT.

Each LDO uses internal 1.2V (LDO+) or –1.2V (LDO–) references with ADJ+ and ADJ– feedback pins enabling adjustable output voltages from ±1.2V to ±32V. The device integrates soft-start, short-circuit current limiting (220mA/160mA), thermal shutdown (>175°C), and requires no external inductors - making it suitable for precision analog biasing where EMI-sensitive operation and compact size are critical.

Key Specifications

Pinout & Package

Package: 18-lead (5mm × 3mm) plastic DFN with exposed GND pad (Pin 19), rated for –40°C to +125°C operating junction temperature. Exposed pad must be soldered to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-polarity regulator applications.

Compared with LT3467EDD#PBF and MAX17242ATP+T, the LTC3265IDHC#PBF uniquely combines inductorless bipolar generation, 100µVRMS noise, 135µA Burst Mode® IQ, and programmable frequency - making it optimal for space-constrained, ultra-low-noise precision analog systems where discrete inductors are undesirable.

Availability

LTC3265IDHC#PBF is available at Aetrix Electronics and suitable for industrial instrumentation, portable test equipment, medical sensor modules, and low-noise audio front-ends requiring stable component supply across extended temperature ranges.

Supply support for LTC3265IDHC#PBF 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

Analog Devices (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors for precision, power, and connectivity applications.

The LTC3265IDHC#PBF belongs to Linear's ultra-low-noise power management portfolio, designed specifically for precision analog systems requiring clean, compact, inductorless bipolar supplies - such as data acquisition, medical imaging, and scientific instrumentation.

FAQ

What is the maximum output current capability of the LTC3265IDHC#PBF?

The LTC3265IDHC#PBF delivers up to 50mA from its positive LDO+ output and up to –50mA from its negative LDO– output. These ratings apply under specified thermal conditions with proper PCB layout and heatsinking. The intermediate charge pump outputs (VOUT+ and VOUT–) support higher peak currents but are not intended as final system supplies - they feed the LDOs, which provide the regulated, low-noise outputs used by sensitive analog circuitry.

How does the MODE pin affect the operation of the LTC3265IDHC#PBF?

The MODE pin selects between two distinct operating modes for both charge pumps: logic-high enables Burst Mode®, where the pumps regulate VOUT+ to 0.94•2•VIN_P and VOUT– to –0.94•VIN_N with ultra-low 135µA quiescent current, at the cost of higher output ripple; logic-low enables constant-frequency mode, where VOUT+ = 2•VIN_P and VOUT– = –VIN_N with fixed 50kHz–500kHz switching, yielding lower ripple but higher IQ. The LTC3265IDHC#PBF must not have MODE left floating.

Can the LTC3265IDHC#PBF generate symmetric ±15V outputs from a 12V input?

Yes - the LTC3265IDHC#PBF can generate symmetric ±15V outputs from a 12V input by connecting VIN_N to VOUT+. In this configuration, the inverting pump produces VOUT– ≈ –VOUT+ ≈ –2•VIN_P = –24V, and the LDO– is adjusted to –15V using its ADJ– feedback network. Simultaneously, the LDO+ is set to +15V via ADJ+. This approach ensures matched noise and regulation performance across both rails, ideal for op-amp dual-supply applications.

What capacitor values are required for stable operation of the LTC3265IDHC#PBF?

For stable operation, the LTC3265IDHC#PBF requires: ≥10µF ceramic input capacitors on VIN_P and VIN_N; ≥1µF ceramic flying capacitors on CBST+/CBST– and CINV+/CINV–; ≥10µF ceramic output capacitors on VOUT+ and VOUT–; and ≥2µF low-ESR ceramic capacitors on LDO+ and LDO– outputs. Optional 100nF bypass capacitors on BYP+ and BYP– further reduce output noise to 100µVRMS. All capacitors must be X7R or better dielectric with voltage ratings exceeding applied rails.

Does the LTC3265IDHC#PBF include built-in protection features?

Yes - the LTC3265IDHC#PBF integrates multiple protection mechanisms: short-circuit current limiting (220mA on VOUT+, 160mA on VOUT–), thermal shutdown (activates at ~175°C junction temperature, resumes at ~165°C), undervoltage lockout on VIN_P (3.4V rising, 3.6V falling), and soft-start circuitry on both charge pumps and LDOs to limit inrush current. These features ensure robust operation in industrial and portable environments without external protection components.