Analog Devices Inc. DC1793A

Overview

DC1793A from Analog Devices is an evaluation board for the LTC3260 low-noise dual-polarity power supply IC. It implements a ±12V output from a single 15V input using an inverting charge pump followed by independent positive and negative LDO regulators, delivering up to 50mA per rail with <100µVRMS output noise and 100µA quiescent current in Burst Mode. It supports industrial instrumentation and portable medical equipment requiring clean bipolar bias.

For engineers reviewing the DC1793A datasheet, DC1793A pinout, DC1793A application, or DC1793A equivalent, this page provides verified layout details, measured performance data, jumper-configurable operating modes (Burst vs constant-frequency), programmable oscillator frequency (50–500kHz), and validated capacitor selection guidance for low-noise bipolar supply design.

Technical Context

The DC1793A implements the full reference design of the LTC3260, including its dual-path architecture: a wide-input (4.5V–32V) inverting charge pump generating VOUT = –VIN (constant frequency mode) or –0.94•VIN (Burst Mode), feeding a dedicated negative LDO (LDO–) while drawing from VIN for the positive LDO (LDO+). Both LDOs are independently enabled via EN+ and EN–, and support adjustable outputs using external resistor dividers referenced to ±1.2V internal references.

It integrates all critical passive components - 1µF flying capacitor (CFLY), 10µF ceramic input/output capacitors (CIN, COUT), 10nF bypass caps on BYP+ and BYP–, and precision feedback resistors (909kΩ/200kΩ/100kΩ) - enabling immediate evaluation of ripple rejection, load transient response, and thermal behavior across –40°C to 125°C operation.

Key Specifications

Availability

DC1793A is available at Aetrix Electronics and suitable for portable medical equipment, industrial instrumentation, low-noise analog front-ends, and battery-powered test gear requiring stable component supply and rapid prototyping of bipolar power architectures.

Supply support for DC1793A 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. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, healthcare, communications, and industrial markets.

The DC1793A belongs to Analog Devices' Power by Linear™ evaluation platform family, designed specifically to accelerate validation of high-efficiency, low-noise power management ICs in demanding analog and mixed-signal applications.

FAQ

What is the primary function of the DC1793A evaluation board?

The DC1793A evaluation board is a fully assembled and tested platform for the LTC3260 dual-polarity power supply IC. It demonstrates ±12V generation from a single 15V input using an inverting charge pump and two independent LDO regulators. The board allows engineers to verify key performance metrics - including output noise (<100µVRMS), quiescent current (100µA in Burst Mode), load regulation, and transient response - without custom PCB development. DC1793A includes all necessary passives, jumpers for mode selection, and test points for direct oscilloscope probing of VLDO+, VLDO–, and VOUT signals.

Can the DC1793A be used to evaluate both DFN and MSOP package variants of the LTC3260?

Yes, the DC1793A features dual footprints supporting both the 14-pin 3mm × 4mm DFN (LTC3260EDE/IDE#PBF) and the 16-pin MSOP (LTC3260EMSE/IMSE/HMSE#PBF) packages. The board's layout adheres to Analog Devices' recommended thermal and routing guidelines for each package type, including proper exposed-pad grounding and minimized trace inductance on high-dI/dt paths (C+, C–, VOUT, LDO–). This enables direct comparison of thermal performance, EMI, and output stability between package options using identical test conditions.

How does the DC1793A implement Burst Mode versus constant-frequency operation?

The DC1793A uses a 0Ω jumper on JP1 to configure the MODE pin of the LTC3260. When JP1 is installed, MODE = VIN (logic high), enabling Burst Mode - where the charge pump cycles intermittently to regulate VOUT ≈ –0.94•VIN and achieves 100µA quiescent current with both LDOs active. When JP1 is removed and MODE is pulled low via onboard resistor, the charge pump operates continuously at fixed 500kHz (or programmed frequency via RT), delivering lower output ripple and higher PSRR at the expense of higher IQ. Measured waveforms on DC1793A confirm these behaviors per Figure 3260 TA01b in the LTC3260 datasheet.

What capacitor values are populated on the DC1793A, and why are they selected?

The DC1793A populates 10µF X7R 0603 ceramic capacitors for CIN, COUT (LDO+ and LDO–), and CLDO+ / CLDO–, plus a 1µF X7R 0603 flying capacitor (CFLY) between C+ and C–. It also includes 10nF NP0/C0G 0402 capacitors on BYP+ and BYP–. These values match Analog Devices' recommended minimums for stability and noise reduction: ≥2µF output capacitance across temperature/voltage, ≥1µF CFLY for full 100mA charge pump output, and 10nF reference bypass caps to suppress 1.2V/–1.2V reference noise - all verified in typical performance curves (Figures G13, G18, G20).

Does the DC1793A support adjustable output voltages, and how is adjustment implemented?

Yes, the DC1793A supports adjustable LDO+ and LDO– outputs via on-board resistor dividers. R1/R2 networks (909kΩ/200kΩ for LDO+, 909kΩ/100kΩ for LDO–) set nominal ±12V outputs using the formulas VLDO+ = 1.2V × (R1/R2 + 1) and VLDO– = –1.2V × (R1/R2 + 1). Test points TP1–TP4 provide access to ADJ+ and ADJ– pins, allowing replacement of R2 with user-selected resistors to achieve other outputs (e.g., ±5V, ±15V) while maintaining LDO stability - consistent with the design equations in LTC3260 datasheet Figures F02 and F03.