Analog Devices Inc./Maxim Integrated MAX853ESA+

Overview

MAX853ESA+ from Maxim Integrated is a low-noise, inverting, regulated charge-pump DC-DC converter designed to generate continuously adjustable negative bias voltages for GaAsFET power amplifiers. It delivers up to 5mA output current across -0.5V to -9.0V with 1mV_p-p output ripple, operates from 4.5V–10V input, and uses an external positive control voltage (V_CTRL) to set V_OUT. It is optimized for cellular handset transmitter amplifier biasing.

For engineers reviewing the MAX853ESA+ datasheet, MAX853ESA+ pinout, MAX853ESA+ application, or MAX853ESA+ equivalent, key selection criteria include its externally controlled output voltage range, ultra-low 1mV_p-p ripple under filtered V_CTRL, logic-level active-low shutdown (<1µA), 100kHz fixed switching frequency, and SO-8 package compatibility with GaAsFET bias circuits requiring stable, low-noise negative regulation.

Technical Context

The MAX853ESA+ implements a two-stage architecture: a capacitive charge pump inverts the input voltage at NEGOUT, followed by an internal N-channel linear regulator that stabilizes and filters the output at OUT. Regulation is achieved via a precision 1.28V internal reference applied to the CONT pin through a resistor divider from OUT to V_CTRL.

Unlike the MAX850–MAX852 family members, the MAX853ESA+ replaces the FB pin with CONT and requires no ground-referenced feedback network - instead, V_OUT is directly proportional to V_CTRL per V_OUT = –V_CTRL × (R2/R1). Its shutdown input is active-low TTL-compatible and reduces supply current to ≤1µA over temperature.

Key Specifications

Pinout & Package

MAX853ESA+ is housed in an 8-pin SO (Small Outline) package measuring 4.9mm × 3.9mm × 1.45mm (max), with standard JEDEC MS-012AC footprint and gull-wing leads. The package is RoHS-compliant and rated for –40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar negative charge-pump regulator applications.

Compared with MAX852ESA+, the MAX853ESA+ trades frequency flexibility for superior ripple performance and direct V_CTRL-based bias tuning; versus LM27762DSGR, it offers 15× lower output ripple and GaAsFET-optimized regulation at the expense of output current and dual-rail capability.

Availability

MAX853ESA+ is available at Aetrix Electronics and suitable for cellular handset design, GaAsFET power amplifier biasing, and portable LCD contrast control requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX853ESA+ 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for demanding industrial, communications, and consumer applications.

The MAX850–MAX853 family was developed specifically to deliver ultra-low-noise, inverting charge-pump regulation for GaAsFET bias in battery-powered RF power amplifiers - prioritizing ripple suppression, shutdown efficiency, and compact integration.

FAQ

What output voltage range does the MAX853ESA+ support, and how is it set?

The MAX853ESA+ supports a continuously adjustable output voltage from –0.5V to –9.0V. This is set using an external positive control voltage (V_CTRL) applied to the CONT pin, along with a resistor divider between OUT and V_CTRL. The relationship is V_OUT = –V_CTRL × (R2/R1). Unlike the MAX850–MAX852, the MAX853ESA+ does not use the FB pin - its regulation is fully controlled via CONT. This enables dynamic bias tuning without hardware changes.

How does the MAX853ESA+ achieve its 1mV_p-p output ripple specification?

The MAX853ESA+ achieves 1mV_p-p typical output ripple through a two-stage architecture: first, a 100kHz charge pump generates an inverted voltage at NEGOUT; second, an internal linear regulator filters and stabilizes this voltage at OUT. Ripple reduction relies critically on a well-filtered V_CTRL signal - noise on CONT directly modulates the output. Using a low-noise, decoupled V_CTRL source and proper PCB layout (short traces, ground plane) is essential to meet the 1mV_p-p spec. The MAX853ESA+ outperforms the MAX850–MAX852 (2mV_p-p) due to tighter CONT-path rejection.

What is the function of the SHDN pin on the MAX853ESA+, and what logic levels activate it?

The SHDN pin on the MAX853ESA+ is an active-low TTL-compatible shutdown control. Driving SHDN ≤0.8V places the MAX853ESA+ into ultra-low-power shutdown mode, reducing supply current to ≤1µA over temperature. Releasing SHDN to ≥2.0V restores normal operation. This pin is electrically identical to the SHDN pin on the MAX850 and MAX851, but differs from the MAX852 (which uses OSC for shutdown gating). The MAX853ESA+'s SHDN interface simplifies integration with baseband processors and microcontrollers lacking open-drain outputs.

Can the MAX853ESA+ be used with a single Li-ion battery, and what is the minimum input voltage for 5mA output?

Yes, the MAX853ESA+ is explicitly designed for single Li-ion (4.2V–3.0V) and 4-cell NiCd/NiMH battery operation. Its input voltage range is 4.5V to 10.0V, so it requires ≥4.5V to maintain full 5mA output capability at all programmed V_OUT levels. At VIN = 4.5V, the maximum achievable |V_OUT| is reduced - for example, at –4.1V output, the device remains functional but may not sustain 5mA across temperature extremes. Datasheet Note 2 confirms that below 4.5V, regulation margin degrades.

What capacitor types and values are recommended for the MAX853ESA+, and why?

Maxim recommends 1µF, ≤0.8Ω ESR ceramic or tantalum capacitors for C1, C2, and C3, and a 10µF, ≤0.2Ω ESR capacitor for C4 (output filter). Low-ESR is critical because the charge pump's effective output resistance - and thus dropout voltage and ripple - scales directly with capacitor ESR at 100kHz. High-ESR caps increase losses, reduce efficiency, and degrade ripple performance. Surface-mount chip ceramics are preferred for C1/C2/C3 due to stability and size; C4 benefits from the bulk capacitance and low ESR of a chip tantalum. All capacitors must be placed close to the MAX853ESA+ pins with short, wide traces.