Analog Devices Inc. LTC1144CS8#PBF

Overview

LTC1144CS8#PBF from Analog Devices (formerly Linear Technology) is a monolithic CMOS switched-capacitor voltage converter that inverts a positive input (2V to 18V) to a complementary negative output (–2V to –18V). It integrates an internal oscillator, divide-by-two logic, voltage level shifter, and four power MOSFETs, requiring only two external capacitors. It delivers up to 20mA load current with 56Ω typical output resistance at 15V input and supports shutdown mode drawing just 8µA.

For engineers reviewing the LTC1144CS8#PBF datasheet, LTC1144CS8#PBF pinout, LTC1144CS8#PBF application, or LTC1144CS8#PBF equivalent, key selection criteria include input voltage range (2V–18V), oscillator frequency control (10kHz base, 10× boostable), shutdown current (8µA), output resistance (≤120Ω), and SOIC-8 package compatibility for space-constrained industrial and data acquisition designs.

Technical Context

The LTC1144CS8#PBF implements a charge-pump topology using internal N-channel and P-channel MOSFET switches controlled by a self-timed oscillator. Its divide-by-two logic ensures precise phase relationship between pump stages, while substrate isolation prevents parasitic turn-on of the N-channel switch. The oscillator frequency is factory-set at ~10kHz (unloaded) and can be increased tenfold via the BOOST pin or reduced via external capacitor on OSC pin.

Operation relies on capacitive energy transfer: CAP+ and CAP– terminals alternately charge and discharge C1 and C2 to generate inverted output at VOUT. Output impedance is dominated by 1/(f × C1) at low frequencies and MOSFET on-resistance at high frequencies - enabling design trade-offs between ripple, efficiency, and load capability across 1kHz–100kHz oscillator range.

Key Specifications

Pinout & Package

Package: 8-Lead Plastic SOIC (S8), 0°C to 70°C operating temperature range, JEDEC MS-012AC compliant, 1.27mm pitch, body size 4.90mm × 3.91mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC1144CS8#PBF, LTC1054CN8#PBF offers 5× higher output current but sacrifices frequency adjustability and SOIC-8 packaging; LTC1046CS8#PBF trades input range and shutdown for lower voltage operation and reduced quiescent draw - making LTC1144CS8#PBF the optimal balance of flexibility, package, and performance for 2V–18V general-purpose inversion.

Availability

LTC1144CS8#PBF is available at Aetrix Electronics and suitable for data acquisition systems, battery-powered instrumentation, RS-232 interface circuits, and industrial analog signal conditioning requiring stable component supply and long-term manufacturability.

Supply support for LTC1144CS8#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 healthcare markets.

The LTC1144CS8#PBF belongs to Linear's legacy switched-capacitor converter family, designed specifically for compact, inductorless negative voltage generation in space- and cost-sensitive applications where magnetic-free solutions are mandatory.

FAQ

What is the maximum continuous output current supported by the LTC1144CS8#PBF?

The LTC1144CS8#PBF delivers up to 20mA continuously at 15V input with ≤56Ω output resistance and maintains stable regulation per Figure TPC06. Absolute Maximum Ratings specify indefinite short-circuit protection only up to V+ ≤ 10V; at 15V input, safe continuous output is limited to 20mA to avoid exceeding 500mW power dissipation and thermal limits in SOIC-8 package.

Can the LTC1144CS8#PBF generate a regulated –5V output from a 9V input?

Yes - the LTC1144CS8#PBF can generate a regulated –5V output from 9V input using the external feedback network shown in Figure 12 (36kΩ/300kΩ resistors). This configuration achieves ±1% output accuracy and <20Ω effective output resistance across 0–5mA load, confirmed in Typical Applications section and TPC09 efficiency curves.

Does the LTC1144CS8#PBF require external diodes for operation?

No - the LTC1144CS8#PBF contains fully integrated CMOS power switches and synchronous rectification logic, eliminating the need for external diodes. This is explicitly stated in the "Typical Applications" section and verified in Figure 8 (Negative Voltage Converter), where no diodes appear in the schematic.

How does the BOOST pin affect oscillator frequency and output performance of the LTC1144CS8#PBF?

Tying the BOOST pin (Pin 1) to V+ increases the LTC1144CS8#PBF's oscillator frequency by approximately 10× - from 10kHz to ~100kHz. This reduces output impedance (e.g., from 56Ω to ~20Ω at 15V/20mA) and lowers ripple voltage, as confirmed in TPC05 and TPC12 performance graphs and Applications Information section.

Is the LTC1144CS8#PBF pin-compatible with the LTC1044 or ICL7660?

No - the LTC1144CS8#PBF has an 8-pin SOIC footprint but differs electrically and functionally from LTC1044 and ICL7660. Pin assignments (e.g., BOOST on Pin 1, OSC on Pin 7) and internal architecture (integrated divide-by-two, substrate isolation logic) are unique. The datasheet positions it as a "High Voltage Upgrade" - indicating functional similarity but not pin compatibility.