Analog Devices Inc. LT1617ES5-1#TRMPBF

Overview

LT1617ES5-1#TRMPBF from Analog Devices (formerly Linear Technology) is a micropower inverting DC/DC converter in a 5-lead SOT-23 package, designed for single-cell battery applications requiring ultra-low input voltage operation down to 1V, 100mA current limiting, and shutdown quiescent current of 0.5µA. It generates negative output voltages up to –34V using a fixed off-time control scheme and integrates a 36V-rated NPN switch with 250mV V_CE(SAT) at 300mA.

For engineers reviewing the LT1617ES5-1#TRMPBF datasheet, LT1617ES5-1#TRMPBF pinout, LT1617ES5-1#TRMPBF application, or LT1617ES5-1#TRMPBF equivalent, this device is selected for space-constrained portable systems needing high-efficiency inversion from 1V–15V inputs - especially LCD bias, handheld computers, digital cameras, and battery backup circuits where minimal footprint and sub-1µA shutdown current are critical.

Technical Context

The LT1617ES5-1#TRMPBF implements a constant off-time (COT) control architecture with a 400ns fixed off-time and internal 12mV current-sense reference (vs. 42mV in LT1617), enabling stable operation across wide load ranges while maintaining 20µA active quiescent current. Its feedback comparator trips at –1.23V with 8mV hysteresis, and regulation relies on external resistor dividers connected to the NFB pin.

It features an integrated 36V NPN power switch with 250mV saturation voltage at 300mA, supports inverting topologies only, and requires external Schottky diodes (e.g., MBR0520/MBR0530) and matched inductors (e.g., 22µH or 47µH). The device operates from –40°C to 85°C and uses a bandgap reference derived from Q1/Q2 and resistive network R3–R6.

Key Specifications

Pinout & Package

LT1617ES5-1#TRMPBF is housed in a 5-lead plastic SOT-23 (S5) package measuring 2.80–3.00mm × 1.90mm × 1.15mm, with gull-wing leads and EIAJ SC-74A compatibility. Pin 1 (SW) connects to the collector of the internal NPN switch; Pin 2 (GND) must tie directly to local ground plane; Pin 3 (NFB) receives feedback voltage; Pin 4 (SHDN) controls enable/disable with logic thresholds of 0.25V (low) and 0.9V (high); Pin 5 (VIN) accepts input supply and requires local 4.7µF ceramic decoupling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1611ES5#TRMPBF and LT1615ES5#TRMPBF, the LT1617ES5-1#TRMPBF uniquely supports 1V start-up and delivers 100mA into –34V rails with sub-1µA shutdown - making it the sole option among these three for true single-cell alkaline/NiMH-powered portable inversion.

Availability

LT1617ES5-1#TRMPBF is available at Aetrix Electronics and suitable for LCD bias generation, handheld computer power, digital camera backlighting, battery backup circuits, and other portable electronics requiring stable component supply with guaranteed long-term sourcing.

Supply support for LT1617ES5-1#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. Linear's legacy design ethos emphasizes high-performance, low-power, and robust integration for demanding industrial and portable applications.

The LT1617ES5-1#TRMPBF belongs to Linear's micropower inverting DC/DC converter family, engineered specifically for battery-powered systems needing high-voltage negative rails from ultra-low input sources - prioritizing start-up reliability, efficiency at light loads, and minimal PCB footprint.

FAQ

What is the minimum input voltage required for LT1617ES5-1#TRMPBF to start switching?

The LT1617ES5-1#TRMPBF starts switching at 1.0V nominal input voltage, as confirmed in the Electrical Characteristics table under "Minimum Input Voltage" for the -1 variant. This enables direct operation from nearly depleted alkaline or NiMH cells, and the device maintains regulation down to 1V across temperature. Below 1V, the internal bandgap reference cannot stabilize, and switching ceases.

Can LT1617ES5-1#TRMPBF generate –34V output safely?

Yes - the LT1617ES5-1#TRMPBF can generate up to –34V output when VIN is ≤1V, because the absolute sum |VIN| + |VOUT| must not exceed the 36V SW pin rating. For example, with VIN = 1V, VOUT = –34V yields 35V at SW, staying within spec. At VIN = 5V, maximum safe VOUT is –31V. Exceeding 36V risks switch breakdown.

What is the purpose of the 100pF feed-forward capacitor in LT1617ES5-1#TRMPBF applications?

The 100pF capacitor placed across the upper feedback resistor (R1) in the LT1617ES5-1#TRMPBF feedback network reduces output voltage ripple by compensating phase lag in the control loop. It improves transient response and suppresses low-frequency oscillation caused by ceramic capacitor ESR zero, particularly in high-gain configurations generating –15V or lower outputs.

Which Schottky diode is recommended for LT1617ES5-1#TRMPBF in a 1V-to–9V application?

For LT1617ES5-1#TRMPBF operating from 1V to –9V (e.g., single-cell alkaline), the Central Semiconductor CMDSH-3 or Phillips BAT54 is recommended - both are 40V-rated, 200mA Schottky diodes with low forward voltage (~0.3V @ 10mA) and fast recovery, matching the low-current, low-VIN profile of the LT1617ES5-1#TRMPBF.

How does the LT1617ES5-1#TRMPBF differ from LT1617ES5#TRMPBF in current limiting?

The LT1617ES5-1#TRMPBF has a 100mA typical switch current limit (75–125mA range), while the LT1617ES5#TRMPBF is rated for 350mA (300–400mA). This difference stems from distinct internal current-sense references: 12mV for the -1 variant vs. 42mV for the base part. Both share identical pinout, package, and feedback reference.