Analog Devices Inc. LTC2927CDDB#TRMPBF

Overview

LTC2927CDDB#TRMPBF from Analog Devices (formerly Linear Technology) is a single-supply power tracking controller IC that enables precise ramp-up and ramp-down sequencing of DC/DC converters without inserting pass elements or degrading transient response. It delivers 0.8V TRACK reference, ±5% current mirror matching between FB and TRACK, 10μA programmable RAMP current, and operates from 2.9V to 5.5V supply - used in FPGA core/I/O supply coordination and multi-rail microprocessor power systems.

For engineers reviewing the LTC2927CDDB#TRMPBF datasheet, LTC2927CDDB#TRMPBF pinout, LTC2927CDDB#TRMPBF application, or LTC2927CDDB#TRMPBF equivalent, key selection criteria include guaranteed 1mA TRACK output drive at VCC = 2.9V, 75mV ON-pin hysteresis for noise-immune sequencing control, ±30mV RAMPBUF offset, and compatibility with point-of-load feedback nodes up to 2.3V clamp voltage.

Technical Context

The LTC2927CDDB#TRMPBF implements an open-loop current-mirror tracking architecture: TRACK pin servos at 0.8V and mirrors current into FB to modulate the slave supply's feedback node, enabling tracking without affecting loop stability. Its RAMP pin accepts either internal 10μA pull-up/pull-down current (set by external capacitor) or external master ramp signal.

Control logic uses a 1.23V ON-pin threshold with 75mV hysteresis to determine ramp direction; SDO provides open-drain shutdown signaling synchronized to VCC UVLO (2.5V) and ON activation; RAMPBUF delivers buffered master signal capable of sourcing/sinking ±2mA to drive resistive TRACK dividers.

Key Specifications

Pinout & Package

Package: 8-lead (3mm × 2mm) plastic DFN (DDB), exposed pad (Pin 9) optional GND connection. Thermal resistance θ_JA = 76°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power supply tracking applications.

Compared with LTC2928CDDB#TRMPBF, the LTC2927CDDB#TRMPBF offers lower cost and simpler layout for single-rail tracking; versus TPS652860RGER, it retains full analog ramp rate control and avoids PMIC vendor lock-in, but requires external DC/DC converters.

Availability

LTC2927CDDB#TRMPBF is available at Aetrix Electronics and suitable for FPGA power management, microprocessor sequencing, and point-of-load supply coordination requiring stable component supply across industrial temperature-limited deployments.

Supply support for LTC2927CDDB#TRMPBF 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 acquired Linear Technology in 2017 and maintains its precision analog and power management portfolio with rigorous automotive and industrial qualification standards.

The LTC2927 belongs to Linear's power supply supervision and sequencing IC family, designed specifically for analog-controlled, high-accuracy tracking of multiple DC/DC outputs in space-constrained, noise-sensitive embedded systems.

FAQ

What is the primary function of the LTC2927CDDB#TRMPBF in a power system?

The LTC2927CDDB#TRMPBF is a precision analog power supply tracking controller that forces a slave DC/DC converter's output to follow a master ramp signal-either generated internally via RAMP pin capacitor or supplied externally-without inserting lossy series elements. Its core function in the LTC2927CDDB#TRMPBF is to mirror current from the 0.8V TRACK node into the FB pin, thereby modulating the slave's feedback node while preserving loop stability and transient response.

How does the ON pin control ramp direction in the LTC2927CDDB#TRMPBF?

The ON pin of the LTC2927CDDB#TRMPBF uses a 1.23V threshold with 75mV hysteresis to determine ramp polarity: when ON rises above 1.23V, a 10μA pull-up current charges the RAMP capacitor for upward tracking; when ON falls below ~1.225V, a 10μA pull-down current discharges it for downward tracking. This direct analog control eliminates need for digital logic or external timers, and the hysteresis prevents oscillation near threshold-critical for reliable LTC2927CDDB#TRMPBF operation in noisy industrial environments.

Can the LTC2927CDDB#TRMPBF track supplies with different feedback reference voltages?

Yes, the LTC2927CDDB#TRMPBF supports variable feedback references via resistor network design: TRACK servo at 0.8V establishes current mirror ratio, while RTA/RTB resistor values scale ramp slope and offset to match slave DC/DCs with FB references ranging from 0.6V (e.g., modern buck controllers) to 1.235V (classic TL431-based designs). The LTC2927CDDB#TRMPBF datasheet provides explicit equations (Eq. 2–5) to calculate RTA/RTB for any target V_FB, ensuring accurate tracking across heterogeneous power stages.

What is the maximum guaranteed TRACK output current for the LTC2927CDDB#TRMPBF at minimum supply voltage?

The LTC2927CDDB#TRMPBF guarantees ≥1mA TRACK output drive at VCC = 2.9V, as confirmed in the Electrical Characteristics table (ITRACK = –1mA condition, VTRACK = 0.77V to 0.82V). This ensures sufficient current to bias standard resistor networks (e.g., 16.5kΩ/13kΩ) for 1.8V and 2.5V rails even under worst-case low-VCC conditions-enabling robust LTC2927CDDB#TRMPBF deployment in brown-out-prone industrial power systems.

Does the LTC2927CDDB#TRMPBF affect the stability of the slave DC/DC converter?

No-the LTC2927CDDB#TRMPBF uses open-loop current mirroring to inject current into the slave's FB node without adding series impedance or altering compensation. Because it presents high impedance (>1GΩ) when tracking completes and does not sink current from the FB node, the LTC2927CDDB#TRMPBF avoids modifying the DC/DC's loop gain or phase margin. Stability validation data in the datasheet (Figure 7 application circuit) confirms unchanged transient response versus standalone operation.