Analog Devices Inc. LTC1530CS8-1.9#PBF

Overview

LTC1530CS8-1.9#PBF from Analog Devices (formerly Linear Technology) is a high-power synchronous buck controller IC designed to regulate 5V or 3.3V input down to a fixed 1.9V output for microprocessor core supplies. It drives two external N-channel MOSFETs, achieves ±2% output voltage regulation over line/load/temperature, supports up to 20A output current, and operates at a fixed 300kHz switching frequency with hiccup-mode current limiting.

For engineers reviewing the LTC1530CS8-1.9#PBF datasheet, LTC1530CS8-1.9#PBF pinout, LTC1530CS8-1.9#PBF application, or LTC1530CS8-1.9#PBF equivalent, key selection criteria include its fixed 1.9V output, topside R_DS(ON)-based current sensing (no external sense resistor), internal soft-start, shutdown quiescent current of 45µA, and SO-8 package compatibility with high-current gate drive requirements.

Technical Context

The LTC1530CS8-1.9#PBF implements a voltage-mode PWM control architecture with a precision 1.235V internal reference, error amplifier transconductance of 2mS (typ), and open-loop DC gain of 54dB (typ). Its feedback loop includes fast-acting MIN/MAX comparators (±3% thresholds) that override the main error amplifier during rapid load transients to maintain stability without compromising compensation.

Current limiting uses the R_DS(ON) of the high-side MOSFET as a sensing element via IFB and IMAX pins, eliminating external shunts. The controller integrates thermal shutdown (trip at ~150°C), undervoltage lockout (3.75V typ), and nonoverlap timing (30–100ns) between G1 and G2 drivers to prevent shoot-through in synchronous buck topologies.

Key Specifications

Pinout & Package

Package: 8-lead plastic SO (SO-8), surface-mount, JEDEC MS-012AC compliant, θ_JA = 130°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck controller applications.

Compared with TPS54620RGYR and ISL6263CRZ-T, the LTC1530CS8-1.9#PBF offers true fixed 1.9V operation without external resistors, proven R_DS(ON) current sensing for high-current reliability, and SO-8 pinout compatibility with existing layouts - making it optimal for industrial and embedded buck regulator upgrades.

Availability

LTC1530CS8-1.9#PBF is available at Aetrix Electronics and suitable for microprocessor core supplies, high-density server VRMs, industrial FPGA power rails, and embedded DSP power systems requiring stable component supply across commercial and industrial temperature grades.

Supply support for LTC1530CS8-1.9#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and computing markets.

The LTC1530CS8-1.9#PBF belongs to Linear's legacy high-current synchronous buck controller family, engineered specifically for efficient, low-noise, high-reliability core voltage regulation in microprocessor and FPGA applications demanding tight DC accuracy and robust fault handling.

FAQ

What is the output voltage tolerance of the LTC1530CS8-1.9#PBF over temperature?

The LTC1530CS8-1.9#PBF delivers a nominal 1.9V output with a guaranteed tolerance of ±1.0% (1.881V–1.919V) at 25°C, and ±1.5% (1.862V–1.938V) across the full industrial temperature range (–40°C to +85°C), as specified in the Electrical Characteristics table for the 'I' grade version. This tight regulation is achieved via precision trimming of the internal 1.235V reference and feedback network.

Does the LTC1530CS8-1.9#PBF require an external current sense resistor?

No, the LTC1530CS8-1.9#PBF does not require an external current sense resistor. It implements topside R_DS(ON) current sensing using the high-side N-channel MOSFET's on-resistance as the sensing element. The IFB and IMAX pins monitor the voltage drop across Q1's drain-to-source path, enabling adjustable current limiting without added power loss or PCB area - a key design advantage of the LTC1530CS8-1.9#PBF.

What is the purpose of the IMAX pin on the LTC1530CS8-1.9#PBF?

The IMAX pin on the LTC1530CS8-1.9#PBF serves as the current limit threshold reference. It sinks a precise 200µA (typical) current with a positive temperature coefficient (3300ppm/°C), which compensates for the negative tempco of MOSFET R_DS(ON). By connecting a resistor from IMAX to VIN, designers set the peak current limit level - a critical function enabling robust overload protection in the LTC1530CS8-1.9#PBF without external components.

Can the LTC1530CS8-1.9#PBF operate with a 5V-only input supply?

Yes, the LTC1530CS8-1.9#PBF can operate with a 5V input, but PVCC must be ≥ VIN + V_GS(ON) of the high-side MOSFET. For 5V-only systems, a charge pump (e.g., doubling topology) is recommended to generate ≥10V at PVCC. Using logic-level MOSFETs rated for R_DS(ON) at V_GS = 4.5V is essential - standard MOSFETs may not fully enhance, causing excessive conduction loss and unreliable current limiting in the LTC1530CS8-1.9#PBF.

What is the shutdown current consumption of the LTC1530CS8-1.9#PBF?

The LTC1530CS8-1.9#PBF draws 45µA (typical) and up to 80µA (max) in shutdown mode, activated by pulling the COMP pin below 100mV. This ultra-low quiescent current enables energy-efficient standby operation in battery-backed or always-on systems. An internal 4µA pull-up on COMP ensures reliable startup when released from shutdown - a verified characteristic of the LTC1530CS8-1.9#PBF across temperature.