Analog Devices Inc. DC1818A

Overview

LTM8001 from Analog Devices is a 36V input, 5A μModule step-down switching regulator with an integrated array of five configurable 1.1A LDOs. It delivers regulated VOUT0 (1.2V–24V) and supports parallelable LDO outputs (VOUT1–VOUT5), enabling multi-rail power for FPGA, ASIC, and RF transceiver applications requiring tight noise control and flexible voltage sequencing.

For engineers reviewing the LTM8001 datasheet, LTM8001 pinout, LTM8001 application, or LTM8001 equivalent, key selection criteria include its 5-output LDO configurability, 90µVRMS output noise (100Hz–1MHz), 3.42mm low-profile BGA package, and support for constant-current/constant-voltage operation in battery charging and precision analog supply designs.

Technical Context

The LTM8001 integrates a fixed-frequency average current-mode buck controller driving a 5A output stage, followed by five independent linear regulators-three powered from VOUT0 (BIAS123) and two from VIN45 (BIAS45). Its ILIM pin enables programmable current limiting (0–6.4A), while SS and RUN pins provide precise soft-start and enable control with hysteresis capability.

Each LDO uses a 10µA SET-pin current source to set output voltage via external resistor (RSET = VOUT / 10µA), supporting zero-volt outputs and parallel operation. Dropout is specified at 100mV (100mA load) to 500mV (1.1A load) between VOUT0/VIN45 and respective LDO outputs, with BIAS123/BIAS45 dropout up to 1.6V at full load.

Key Specifications

Pinout & Package

The LTM8001 is housed in a 121-pad, 15mm × 15mm × 3.42mm overmolded BGA package with SnPb or RoHS-compliant SAC305 finish. Thermal performance relies on GND pad thermal vias and bottom-side copper area per JEDEC JESD51-9/12 standards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-output PMIC applications.

Compared with LTM4644IY#PBF and TPS650860ARSLR, the LTM8001 uniquely combines 5A buck capability with five 1.1A LDOs in one BGA, enabling compact, low-noise, multi-rail solutions without external LDOs or complex sequencing ICs - critical for space-constrained RF and FPGA systems.

Availability

LTM8001 is available at Aetrix Electronics and suitable for FPGA power delivery, RF transceiver biasing, and supercapacitor charging applications requiring stable component supply, long-term lifecycle support, and RoHS/SnPb packaging options.

Supply support for LTM8001 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 industrial, communications, automotive, and healthcare markets.

The LTM8001 belongs to Analog Devices' µModule regulator product line - engineered for high-density, turnkey power solutions that integrate magnetics, MOSFETs, and control circuitry into compact, thermally optimized packages for demanding embedded and infrastructure applications.

FAQ

What is the maximum allowable input voltage for the LTM8001?

The absolute maximum input voltage on the VIN0 pin is 40V, but the recommended operating range is 6V to 36V. Exceeding 36V may trigger overvoltage protection or cause permanent damage. For reliable operation in automotive or industrial environments with transient spikes, ensure external clamping or filtering keeps VIN0 ≤36V under all conditions. The LTM8001 datasheet specifies 36VIN as the functional rating, and the LTM8001 must not be operated continuously above this value.

Can the LTM8001's LDO outputs be paralleled, and what is required?

Yes, the LTM8001's five LDO outputs (VOUT1–VOUT5) can be paralleled by connecting their SET pins together and tying their VOUT pins together. A single SET resistor (RSET = VOUT / (10µA × n), where n = number of paralleled LDOs) sets the shared output voltage. All paralleled LDOs must share the same BIAS supply (BIAS123 or BIAS45) and load current is distributed based on matching output impedance. The LTM8001 supports up to 5.5A total LDO current when all five are paralleled.

How does the ILIM pin affect the LTM8001's output current limit?

The ILIM pin on the LTM8001 accepts a 0V–1.5V analog voltage to scale the maximum regulated output current from 0A to 6.4A. At 1.5V, the current limit is 6.4A (±1.2% accuracy); at 0.75V, it is 3.4A. Voltages above 1.5V have negligible effect. This enables precise CC/CV operation for battery or supercapacitor charging. The LTM8001 defaults to ~5A when ILIM is tied to VREF (2V), and the ILIM function remains active even if RUN is asserted.

What is the minimum load requirement for stable regulation of the LTM8001's LDO outputs?

The LTM8001's LDO outputs (VOUT1–VOUT5) require a minimum load current of 1mA to maintain regulation - unless the LDO is disabled (e.g., BIAS123 = 0V or VOUT0 = 0V). This applies across the full output voltage range (0V–24V). For zero-volt outputs, the 1mA load must be returned to a negative supply to avoid reverse current. The LTM8001 datasheet explicitly states "no minimum load is required if the respective linear regulator is off", confirming load dependency is conditional on bias activation.

Does the LTM8001 support synchronization to an external clock, and how is it configured?

Yes, the LTM8001 supports external clock synchronization via the SYNC pin. To use it, apply a logic-level square wave (0.8V–1.2V thresholds) at the desired switching frequency, and configure the RT resistor to set the internal oscillator 20% slower than the SYNC frequency. The SYNC pin must never be left floating - tie to GND if unused. This feature enables EMI reduction through frequency dithering or alignment with system clocks. The LTM8001 maintains phase lock across input/output transients and supports frequencies up to 1MHz.