Analog Devices Inc. LTC3863MPDE#TRPBF

Overview

LTC3863MPDE#TRPBF from Analog Devices is a robust, high-voltage inverting DC/DC PMOS controller optimized for automotive and industrial power supplies. It drives an external P-channel MOSFET to generate negative output voltages from –0.4V to –150V, operates from 3.5V to 60V input, draws only 70µA quiescent current in Burst Mode, and supports programmable switching frequency from 50kHz to 850kHz. It is used in telecom and distributed power systems requiring stable negative bias rails.

For engineers reviewing the LTC3863MPDE#TRPBF datasheet, LTC3863MPDE#TRPBF pinout, LTC3863MPDE#TRPBF application, or LTC3863MPDE#TRPBF equivalent, key selection considerations include its –55°C to 150°C operating junction temperature range, 12-lead 4mm × 3mm DFN package with exposed PGND pad, peak current mode control architecture, and verified adjacent-pin FMEA for safety-critical designs.

Technical Context

The LTC3863MPDE#TRPBF implements a nonsynchronous inverting peak current mode PWM controller with an internal transconductance error amplifier (1.8mS), programmable soft-start/tracking via SS pin, and dual light-load modes: Burst Mode (70µA IQ) and pulse-skipping. Its gate driver delivers strong pull-up (2Ω) and pull-down (0.9Ω) capability for high-side P-MOSFETs, with VIN–VCAP regulated to 8V (±0.5V) for efficient switching.

Safety features include overvoltage lockout (10% VFB threshold), frequency foldback triggered below 0.4V on VFB (down to 18% of set frequency), and undervoltage lockout with 3.25V hysteresis. The device supports phase-lockable synchronization from 75kHz to 750kHz and offers accurate current limit sensing (95mV typical V_ILIM) with Kelvin sense routing support.

Key Specifications

Pinout & Package

Package: 12-lead (4mm × 3mm) plastic DFN with exposed PGND pad (Pin 13), thermally enhanced for high-power density operation. Exposed pad must be soldered to PCB for electrical continuity and thermal performance (θ_JA = 43°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inverting DC/DC controller applications.

Compared with LTC3863MPDE#TRPBF, LTC3864MPDE#TRPBF lacks inverting functionality but offers tighter VFB tolerance (±0.5%) for precision positive rails, while LM5180QPWRQ1 provides inherent isolation at the cost of board area and complexity - making LTC3863MPDE#TRPBF the optimal choice for compact, efficient, non-isolated negative voltage conversion.

Availability

LTC3863MPDE#TRPBF is available at Aetrix Electronics and suitable for automotive infotainment, industrial sensor conditioning, telecom line card bias, and distributed power architecture applications requiring stable component supply across extended temperature and high-reliability environments.

Supply support for LTC3863MPDE#TRPBF 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC3863MPDE#TRPBF belongs to Analog Devices' Power by Linear™ high-voltage DC/DC controller family, designed specifically for robust, wide-input-range power conversion in safety-critical automotive and industrial systems.

FAQ

What is the operating temperature range of the LTC3863MPDE#TRPBF?

The LTC3863MPDE#TRPBF is fully specified and tested over an operating junction temperature range of –55°C to 150°C. This extended grade qualifies it for under-hood automotive applications, industrial motor drives, and aerospace subsystems where extreme thermal environments are encountered. Its DFN package with exposed PGND pad ensures reliable thermal performance at high ambient temperatures.

How does the LTC3863MPDE#TRPBF achieve negative output voltage generation?

The LTC3863MPDE#TRPBF generates negative output voltage using an inverting topology with an external P-channel MOSFET and Schottky catch diode. It senses the negative output via the VFBN and VFB pins using a resistor divider, where VFB is regulated to 0.800V and VFBN serves as the 0V reference node. The resulting output is VOUT = –(RFB1/RFB2) × 0.800V, enabling precise, stable negative rail generation without additional ICs.

Can the LTC3863MPDE#TRPBF be synchronized to an external clock?

Yes, the LTC3863MPDE#TRPBF supports external clock synchronization via the PLLIN/MODE pin. When an external clock signal (75kHz to 750kHz) with logic-high ≥2V and logic-low ≤0.5V is applied, the internal phase-locked loop aligns the GATE turn-on edge to the rising edge of that clock. This feature enables EMI reduction through frequency dithering and system-level timing coordination in multi-converter power architectures.

What protection features are built into the LTC3863MPDE#TRPBF?

The LTC3863MPDE#TRPBF integrates overvoltage protection (OVP) triggering at +10% VFB, overcurrent/short-circuit protection with frequency foldback (active below 0.4V on VFB), and input undervoltage lockout (UVLO) with 3.25V threshold and 0.25V hysteresis. These features ensure safe startup, fault containment, and robust operation in unregulated or noisy input environments without external supervision circuitry.

What is the purpose of the CAP pin on the LTC3863MPDE#TRPBF?

The CAP pin on the LTC3863MPDE#TRPBF provides the regulated bias supply for the internal P-channel MOSFET gate driver. An internal LDO maintains VIN–VCAP at 8.0V ±0.5V (for VIN > 8V), enabling efficient high-side switching. A minimum 0.1µF low-ESR ceramic capacitor must be placed between VIN and CAP to stabilize the LDO and suppress switching noise - improper CAP decoupling causes gate drive instability and reduced efficiency.