Analog Devices Inc. LTM4709HY#PBF

Overview

LTM4709HY#PBF from Analog Devices is a triple-output, 3A per channel ultralow-noise µModule linear regulator with configurable digital voltage selection, 45mV typical dropout at 3A, 1.3μVRMS output noise (10Hz–100kHz), and 51dB PSRR at 1MHz - designed for post-regulation of FPGA core, RF PLL, and high-precision ADC/DAC supplies.

For engineers reviewing the LTM4709HY#PBF datasheet, LTM4709HY#PBF pinout, LTM4709HY#PBF application, or LTM4709HY#PBF equivalent, key selection criteria include its H-grade 150°C junction rating, 98-pin BGA package with Kelvin sense capability, ±1.5% output regulation over line/load/temperature, and support for parallel operation to deliver up to 9A total output current.

Technical Context

The LTM4709HY#PBF integrates three independent low-dropout linear regulators in a single 6mm × 12mm × 1.92mm BGA package, each featuring an N-channel source-follower pass transistor architecture enabling ultrafast transient response and minimal external components. Its internal reference includes integrated 2.2µF ceramic capacitors, eliminating need for external CREF in most applications.

Each channel supports digitally programmable output voltages from 0.5V to 4.2V via tri-state VOx0/VOx1/VOx2 pins, with 50mV steps below 1.2V and 100mV steps up to 1.8V, plus discrete levels at 2V, 2.5V, 3V, 3.3V, and 4.2V. The VIOC1 pin enables input-to-output voltage control of upstream switching regulators to optimize efficiency while preserving PSRR performance.

Key Specifications

Pinout & Package

The LTM4709HY#PBF is housed in a 98-pin BGA package measuring 6mm × 12mm × 1.92mm with 0.8mm ball pitch and thermal performance characterized at θJCbottom = 3°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-output linear regulator applications.

Compared with LTM4709EY#PBF and LTM4709IY#PBF, the LTM4709HY#PBF provides verified 150°C junction operation - critical for sealed enclosures, high-power-density servers, and aerospace edge computing where thermal headroom is constrained and long-term reliability at elevated temperature must be assured.

Availability

LTM4709HY#PBF is available at Aetrix Electronics and suitable for high-reliability FPGA power delivery, RF transceiver biasing, and medical imaging subsystems requiring stable component supply with full lifecycle support.

Supply support for LTM4709HY#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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, communications, and industrial markets.

The LTM4709HY#PBF belongs to Analog Devices' µModule regulator family - engineered for high-density, low-noise power delivery in space-constrained, thermally demanding applications such as advanced FPGAs, RF systems, and medical electronics.

FAQ

What is the maximum junction temperature rating for the LTM4709HY#PBF?

The LTM4709HY#PBF is H-grade rated with a maximum junction temperature of 150°C, validated over the full –40°C to +150°C operating range. This exceeds the 125°C rating of E- and I-grade variants and enables deployment in sealed, high-power-density systems where ambient temperatures exceed 85°C. Thermal derating curves in the datasheet define safe output current limits at elevated ambient conditions.

How does the VIOC1 pin function in the LTM4709HY#PBF?

The VIOC1 pin on the LTM4709HY#PBF enables input-to-output voltage control of an upstream switching regulator to minimize power dissipation while preserving PSRR. It outputs a voltage equal to (VIN – VOUT) + 800mV and connects directly to the feedback node of the buck converter. This ensures constant VIN–VOUT differential - critical for maintaining 51dB PSRR at 1MHz while maximizing system efficiency. Only Channel 1 supports VIOC.

Can the LTM4709HY#PBF channels be paralleled for higher current?

Yes, the LTM4709HY#PBF supports paralleling multiple devices or channels to deliver up to 9A total output current. When paralleling, connect all VIOC1 pins to the same upstream buck feedback node to ensure synchronized VIN–VOUT control. Kelvin sense (VOUTS) pins must be tied to the common load point, and output voltage select pins (VOx0–VOx2) must be matched across paralleled channels to avoid current imbalance.

What is the accuracy of the current monitor in the LTM4709HY#PBF?

The LTM4709HY#PBF provides a precision current monitor with ±2.4% accuracy at 3A per channel. The IMONx pins source a current equal to IOUT/3000 (e.g., 1mA at 3A), allowing measurement via an external resistor to ground. Accuracy is specified over the full –40°C to +150°C junction temperature range and includes gain and offset error contributions. IMON shutdown current is <1μA when EN is low.

Does the LTM4709HY#PBF require external reference bypass capacitors?

No, the LTM4709HY#PBF integrates 2.2µF ceramic capacitors internally between each VREFx pin and GND, eliminating the need for external reference bypass capacitors in most applications. These internal capacitors provide sufficient filtering for ultralow 1.3μVRMS noise (10Hz–100kHz) and soft-start functionality. An optional external CREF may be added only if sub-1kHz noise reduction is required.