Analog Devices Inc. LT1617ES5-1#TRPBF

Overview

LT1617ES5-1#TRPBF 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 with 1V to 15V input range, 100mA current limit, and –34V maximum output voltage. It delivers 2.5mA at –9V from 1V–1.5V input in handheld LCD bias circuits.

For engineers reviewing the LT1617ES5-1#TRPBF datasheet, LT1617ES5-1#TRPBF pinout, LT1617ES5-1#TRPBF application, or LT1617ES5-1#TRPBF equivalent, key selection criteria include its 1V minimum input capability, 0.5µA shutdown quiescent current, fixed 400ns off-time control, –1.23V feedback reference, and compatibility with low-profile 22µH/47µH inductors in space-constrained portable designs.

Technical Context

The LT1617ES5-1#TRPBF implements a constant off-time current-mode control architecture with internal NPN power switch (36V rating), 8mV feedback hysteresis, and 12mV current-sense threshold for 100mA limiting. Its bandgap-regulated feedback comparator (–1.23V trip point) enables precise negative output regulation without external references.

Operation relies on synchronous inductor charging during switch-on and capacitor-fed discharge during 400ns fixed off-time, supporting high efficiency across 0.1–30mA loads. The device enters <1µA shutdown when SHDN pin voltage drops below 0.25V, and resumes regulation only after NFB voltage falls below –1.23V minus hysteresis.

Key Specifications

Pinout & Package

LT1617ES5-1#TRPBF uses a 5-lead plastic SOT-23 (S5) package measuring 2.80–3.00mm × 1.90mm × 1.15mm, optimized for automated placement and minimal PCB area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1617ES5-1#TRPBF, LT1611ES5#TRPBF offers higher output current but sacrifices ultra-low-voltage start-up capability, while MAX764CSA+ trades size and quiescent performance for SO-8 compatibility-neither matches the LT1617ES5-1#TRPBF's combination of 1V operation, –34V output, and 0.5µA shutdown in SOT-23.

Availability

LT1617ES5-1#TRPBF is available at Aetrix Electronics and suitable for LCD bias generation, handheld computer power, and battery backup systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LT1617ES5-1#TRPBF 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 LT1617 family was designed specifically for micropower inverting DC/DC conversion in space-constrained portable electronics, emphasizing ultra-low input voltage operation and high negative output voltage capability.

FAQ

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

The LT1617ES5-1#TRPBF starts switching at 1.0V input, verified across temperature and process corners. This 1V minimum enables operation from nearly depleted single-cell alkaline or NiMH batteries, unlike the LT1617 variant which requires ≥1.2V. Startup behavior is guaranteed per Electrical Characteristics table, with no external components needed to achieve this threshold.

How does LT1617ES5-1#TRPBF achieve –34V output without exceeding its 36V switch voltage rating?

The LT1617ES5-1#TRPBF achieves –34V output by leveraging the inverting topology where the SW pin sees only VIN + |VOUT|. With a maximum 15V input, the worst-case SW voltage is 15V + 34V = 49V-exceeding the 36V absolute maximum. Therefore, –34V output is only valid when VIN ≤ 2V (e.g., 2V + 34V = 36V). The datasheet specifies "up to –34V" under appropriate input constraints, not universally.

Can LT1617ES5-1#TRPBF be used in a charge pump configuration?

No-LT1617ES5-1#TRPBF is strictly an inductor-based inverting switching regulator, not a charge pump IC. Its block diagram shows a single NPN switch, feedback comparator, and one-shot timer driving inductors L1/L2. Charge pump topologies require flying capacitors and dual-phase switches, which the LT1617ES5-1#TRPBF does not implement or support.

What is the purpose of the 100pF feed-forward capacitor sometimes shown in LT1617ES5-1#TRPBF application circuits?

The 100pF feed-forward capacitor, placed across the upper feedback resistor (R1), improves transient response and reduces output voltage ripple by injecting high-frequency error signal directly into the NFB node. For LT1617ES5-1#TRPBF, this capacitor compensates for phase lag introduced by the RC network, especially in high-gain configurations like –33V outputs, cutting ripple by up to 50% without increasing output capacitance.

Is LT1617ES5-1#TRPBF pin-compatible with LT1617ES5#TRPBF?

Yes-LT1617ES5-1#TRPBF and LT1617ES5#TRPBF share identical 5-lead SOT-23 pinout (SW/GND/NFB/SHDN/VIN), same marking layout, and identical thermal and package dimensions. However, they differ electrically: LT1617ES5-1#TRPBF has 100mA current limit and 1V min input, while LT1617ES5#TRPBF has 350mA limit and 1.2V min input. Interchangeability requires verifying current and input voltage requirements.