Analog Devices Inc. LTC3896IFE

Overview

LTC3896IFE from Analog Devices is a 4-quadrant, bidirectional DC/DC controller IC designed for bipolar power supplies that source and sink current across ±10 V output rails at up to 3 A. It operates with an intermediate bus input (V_INTER) of 12 V to 24 V, supports synchronous N- and P-channel MOSFET drive, and features voltage-mode control with external feedback via the FB pin. It enables regenerative braking and audio test equipment requiring seamless polarity reversal.

For engineers reviewing the LTC3896IFE datasheet, LTC3896IFE pinout, LTC3896IFE application, or LTC3896IFE equivalent, key selection considerations include its 4-quadrant operation capability, ±10 V programmable output range, 200 kHz fixed switching frequency, integrated gate drivers for QN1/QP1, and dedicated current-sense inputs (ISP/ISN) enabling precise bidirectional current regulation in both sourcing and sinking modes.

Technical Context

The LTC3896IFE implements voltage-mode control architecture with independent high-side (TG) and low-side (BG) gate drivers optimized for complementary N- and P-channel MOSFETs in a 4-quadrant topology. It accepts a bipolar control voltage (0.1 V to 1.048 V) at the CTRL pin to linearly set output voltage from –10 V to +10 V while maintaining regulation via the FB pin and external RFB divider.

Current sensing is performed differentially across RS2 using ISP and ISN pins for reverse-current (sink) mode, with internal comparator reference set to 50 mV. The device does not integrate a PWM modulator or error amplifier - all loop compensation and control logic are external, enabling full design flexibility for automotive cold-crank resilient bipolar supplies.

Key Specifications

Pinout & Package

The LTC3896IFE is housed in a 28-pin 4 mm × 5 mm exposed-pad thermally enhanced TSSOP package (FE suffix), with pin 1 marked by dot and pin numbering counterclockwise.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-quadrant controller applications.

Compared with LT8714, the LTC3896IFE offers greater external loop flexibility and tighter control over bipolar transition dynamics but requires more external components; compared with LTC7804, it performs fundamentally different 4-quadrant regulation rather than unidirectional boosting - they serve complementary roles in the same system.

Availability

LTC3896IFE is available at Aetrix Electronics and suitable for automotive regenerative braking interfaces, audio test signal generators, industrial actuator drivers, and lab-grade dual-rail source/sink modules requiring stable component supply and long-term production continuity.

Supply support for LTC3896IFE 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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The LTC3896IFE belongs to ADI's Power by Linear™ high-voltage controller family, engineered specifically for precision bipolar and bidirectional power conversion in safety-critical and high-reliability systems.

FAQ

What is the primary function of the LTC3896IFE in a power system?

The LTC3896IFE is a 4-quadrant DC/DC controller IC that enables a single output terminal to both source and sink current while delivering programmable bipolar voltages from –10 V to +10 V. It does not regulate input voltage - instead, it requires a stable intermediate bus (V_INTER = 12 V–24 V) and controls external N- and P-channel MOSFETs to achieve bidirectional power flow. Its core role is precise, fast-transitioning bipolar regulation in applications like regenerative braking and audio test equipment.

Does the LTC3896IFE support direct connection to a 5 V–24 V input rail?

No, the LTC3896IFE does not accept 5 V–24 V directly. It requires a pre-regulated intermediate bus (V_INTER) between 12 V and 24 V, typically supplied by a companion boost controller such as the LTC7804. The LTC3896IFE itself only manages the final 4-quadrant stage - its VIN pin is for bias supply only (INTVcc), not main power input. Attempting direct wide-input connection will damage the LTC3896IFE or cause malfunction.

How is output voltage programmed on the LTC3896IFE?

Output voltage on the LTC3896IFE is programmed linearly via an analog control voltage applied to the CTRL pin, ranging from 0.1 V (for –10 V output) to 1.048 V (for +10 V output). This mapping is fixed and monotonic, enabling smooth zero-crossing transitions. The FB pin provides closed-loop voltage regulation using an external resistor divider, while SENSE+ and SENSE− ensure Kelvin sensing accuracy. No digital interface or register programming is involved.

Can the LTC3896IFE regulate current during reverse-power operation?

Yes, the LTC3896IFE regulates output current during reverse-power (sink) operation using its ISP and ISN pins to monitor the voltage drop across a dedicated sense resistor (RS2). It maintains a fixed 50 mV threshold across RS2, adjusting duty cycle to hold current constant regardless of V_INTER or load conditions. This enables precise regenerative current control - essential for automotive braking energy recovery and lab-grade current sourcing/sinking.

What package type and thermal characteristics does the LTC3896IFE have?

The LTC3896IFE is packaged in a 28-pin 4 mm × 5 mm thermally enhanced TSSOP (FE suffix) with exposed pad for improved heat dissipation. When mounted on a standard 2-layer PCB with 2 oz copper and minimal thermal relief, it supports continuous 3 A operation at ambient temperatures up to +70°C. The exposed pad must be soldered to a solid thermal plane and tied to GND for optimal performance and reliability in sustained bidirectional operation.