Analog Devices Inc. DC1089B

Overview

DC1089B from Analog Devices (formerly Linear Technology) is a demonstration circuit built around the LT3502A monolithic step-down DC/DC regulator IC, delivering 4.98V ±3% at up to 500mA from a 7V–40V input. It features 2.25MHz fixed-frequency current-mode control, internal boost diode, and soft-start programmability via the SHDN pin. Designed for automotive battery and 24V industrial supply evaluation, it enables rapid validation of high-frequency buck regulation in space-constrained systems.

For engineers reviewing the DC1089B datasheet, DC1089B pinout, DC1089B application, or DC1089B equivalent, key selection considerations include its 7V–40V input range, 500mA output capability, 2.25MHz switching frequency, internal diode integration, and transient response performance under 150mA→400mA load steps.

Technical Context

The DC1089B implements the LT3502A's constant-frequency current-mode architecture, enabling stable loop behavior and fast transient response with minimal external components. Its feedforward capacitor optimization improves load-step recovery, as verified in 12V-input, 5V-output testing with 10μs/div oscilloscope capture.

Protection functions include cycle-by-cycle current limiting, frequency foldback during overload, and DA-pin-based diode-current fault sensing-directly inherited from the LT3502A silicon. The board uses no external boost diode, leveraging the IC's integrated solution to reduce BOM count and footprint.

Key Specifications

Availability

DC1089B is available at Aetrix Electronics and suitable for automotive infotainment power validation, industrial PLC I/O module prototyping, and 24V-powered IoT gateway development requiring stable component supply and documented reference design fidelity.

Supply support for DC1089B 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. (including legacy Linear Technology products) is a global semiconductor company specializing in high-performance analog, mixed-signal, and power management solutions for precision and power-critical applications.

The DC1089B belongs to Analog Devices' demonstration circuit portfolio for monolithic DC/DC regulators, engineered to accelerate evaluation of high-frequency buck converters in real-world input voltage and load conditions.

FAQ

What is the primary function of the DC1089B demonstration circuit?

The DC1089B demonstration circuit implements the LT3502A step-down regulator to provide a fully assembled, tested platform for evaluating 5V/500mA power conversion from 7V–40V inputs. It validates key behaviors including efficiency, ripple, transient response, and protection features-enabling rapid design-in of the LT3502A without custom PCB development. The DC1089B includes all necessary passive components, layout-optimized routing, and test points for direct measurement.

Does the DC1089B support soft-start functionality, and how is it configured?

Yes, the DC1089B supports soft-start via the LT3502A's SHDN pin, which is routed to an external RC filter on the board. Driving this pin with a voltage ramp delays the enable timing, reducing inrush current during startup. This configuration is implemented per the LT3502A datasheet and verified in the DC1089B quick start guide. The DC1089B's JP1 jumper enables this mode when set to ON.

What input voltage sources are compatible with the DC1089B?

The DC1089B accepts input voltages from 7V to 40V DC, making it compatible with nominal 12V and 24V automotive batteries (including cold-crank and load-dump transients within limits), industrial 24V supplies, and wide-range lab power sources. Input overvoltage must be limited to ≤40V, as specified in the DC1089B quick start guide. The DC1089B's design ensures stable operation across this full range without external LDO pre-regulation.

How is output voltage accuracy maintained on the DC1089B?

The DC1089B achieves 4.98V ±3% output voltage accuracy using the LT3502A's internal 1.215V reference and precision external resistor divider (R1/R2). The feedback network is laid out with tight thermal coupling and low parasitic impedance to minimize drift. This accuracy is confirmed under 12V input and 500mA load per the DC1089B performance summary. No user trimming is required-the DC1089B ships calibrated.

Can the DC1089B be used to evaluate transient response, and what test conditions apply?

Yes, the DC1089B is optimized for transient response evaluation, with a feedforward capacitor included per the LT3502A datasheet recommendations. Figure 3 in the DC1089B quick start guide shows measured response to a 150mA→400mA load step at 12V input and 5V output, captured at 10μs/div. The DC1089B's layout and component selection ensure repeatable, low-noise measurements without probe-ground-loop artifacts.