Analog Devices Inc. LTC1144IN8#PBF

Overview

LTC1144IN8#PBF from Analog Devices (formerly Linear Technology) is a monolithic CMOS switched-capacitor voltage converter that inverts a positive input (2V–18V) to a complementary negative output (–2V to –18V). It integrates four power MOSFETs, an internal oscillator, divide-by-two logic, and level shifter. Requires only two external capacitors and delivers ≤120Ω output resistance at 15V input/20mA load - ideal for generating regulated –15V rails in data acquisition systems.

For engineers reviewing the LTC1144IN8#PBF datasheet, LTC1144IN8#PBF pinout, LTC1144IN8#PBF application, or LTC1144IN8#PBF equivalent, key selection criteria include shutdown current (8µA), oscillator frequency control (10kHz base, 10× boostable), open-circuit conversion efficiency (99.9%), and compatibility with wide-input battery or wall-adapter-powered systems requiring low-noise negative supplies.

Technical Context

The LTC1144IN8#PBF implements a charge-pump topology using internal N-channel MOSFET switches controlled by a self-timed oscillator. Its divide-by-two stage ensures precise phase relationship between pump capacitor switching cycles, minimizing ripple and preventing substrate turn-on via dedicated logic protection.

Oscillator frequency is user-adjustable: fixed at 10kHz (unloaded), reduced via external capacitor on OSC (Pin 7), or boosted 10× by tying BOOST (Pin 1) to V+. Output impedance scales inversely with both f_OSC and C₁, enabling design trade-offs between load regulation and EMI.

Key Specifications

Pinout & Package

Package: 8-Lead Plastic DIP (N8), –40°C to +85°C industrial temperature range, 100°C/W thermal resistance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar switched-capacitor inverter applications.

Compared with LTC1054CN8#PBF and LTC1046CS8#PBF, the LTC1144IN8#PBF uniquely balances wide 2V–18V input, 8µA shutdown, and industrial temperature range in a through-hole DIP package - making it optimal for cost-sensitive, medium-current, battery-plus-wall-adapter designs where layout simplicity and thermal robustness are prioritized.

Availability

LTC1144IN8#PBF is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor interfaces, and automotive infotainment systems requiring stable component supply across extended temperature ranges and mixed power-source environments.

Supply support for LTC1144IN8#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 acquired Linear Technology in 2017 and maintains its legacy precision analog portfolio, emphasizing high-reliability signal conditioning and power management ICs for demanding industrial and aerospace applications.

The LTC1144 product line was designed specifically for compact, low-component-count negative voltage generation in space-constrained systems where efficiency, shutdown capability, and wide input range outweigh the need for regulation or high output current.

FAQ

What is the maximum safe input voltage for LTC1144IN8#PBF?

The LTC1144IN8#PBF has an absolute maximum supply voltage rating of 20V transient and 18V continuous operation. Exceeding 18V during normal operation risks permanent damage. For designs powered from unregulated sources like automotive batteries or wall adapters, ensure input filtering or clamping keeps V+ within this limit. The LTC1144IN8#PBF does not include overvoltage protection circuitry.

Can LTC1144IN8#PBF generate regulated output voltages?

The LTC1144IN8#PBF is an unregulated charge-pump inverter - its output voltage magnitude equals the input voltage magnitude (VOUT ≈ –V+), with load-dependent droop defined by output resistance. To achieve regulation, external circuitry such as an op-amp-based feedback network (as shown in Figure 12 of the datasheet) is required. The LTC1144IN8#PBF itself provides no internal voltage reference or error amplifier.

How does BOOST pin operation affect LTC1144IN8#PBF performance?

Tying the BOOST pin (Pin 1) of the LTC1144IN8#PBF to V+ increases oscillator frequency by approximately 10×, raising it from 10kHz to ~100kHz. This reduces effective output resistance (e.g., from 56Ω to ~20Ω at 15V/20mA) and lowers output ripple, improving load regulation - but increases switching losses and reduces power conversion efficiency above ~50kHz. The LTC1144IN8#PBF's BOOST function is digital, not analog; no intermediate frequencies are supported.

Is LTC1144IN8#PBF compatible with ceramic capacitors for C1 and C2?

Yes, the LTC1144IN8#PBF supports ceramic capacitors for C1 and C2, though aluminum or tantalum electrolytics are recommended per the datasheet for cost and size efficiency. Ceramic capacitors will work but may increase output ripple due to lower ESR and require careful PCB layout to avoid resonance. The LTC1144IN8#PBF does not specify minimum ESR, so 10µF X7R ceramics with ≥1Ω ESR are preferred over ultra-low-ESR types.

What is the thermal performance of LTC1144IN8#PBF in its N8 package?

The LTC1144IN8#PBF in the 8-lead plastic DIP (N8) package has a junction-to-ambient thermal resistance (θ_JA) of 100°C/W. At maximum 500mW power dissipation and 85°C ambient, junction temperature reaches 165°C - exceeding the 110°C T_JMAX. Derating is essential: at 85°C ambient, max continuous power is limited to 250mW. The LTC1144IN8#PBF's thermal design requires adequate copper pour and airflow for reliable industrial operation.