Analog Devices Inc. ADP1872ARMZ-1.0-R7

Overview

ADP1872ARMZ-1.0-R7 from Analog Devices is a synchronous current-mode PWM buck controller with constant on-time architecture, designed for high-efficiency DC/DC conversion in space-constrained power supplies. It operates at 1.0 MHz switching frequency, supports input voltages up to 20 V, regulates output down to 0.6 V with ±1.0% reference accuracy, and drives all-N-channel MOSFET power stages - enabling use in DSP core supplies and telecom point-of-load applications.

For engineers reviewing the ADP1872ARMZ-1.0-R7 datasheet, ADP1872ARMZ-1.0-R7 pinout, ADP1872ARMZ-1.0-R7 application, or ADP1872ARMZ-1.0-R7 equivalent, this controller delivers valley current-mode control, integrated bootstrap diode, resistor-programmable current-sense gain, thermal overload protection, and precharged-load startup capability - critical for stable, high-transient-response 1.0 MHz buck designs.

Technical Context

The ADP1872ARMZ-1.0-R7 implements a valley current-mode control scheme with pseudo-fixed frequency operation, enabling optimal stability and transient response at low duty cycles. Its constant on-time architecture eliminates need for external current-sense resistors and supports wide VIN range (3.0 V to 20 V) while maintaining regulation down to 0.6 V output.

It integrates a bootstrap diode for high-side gate drive, features precision enable input with 235–330 mV threshold and 35 mV hysteresis, and provides programmable current-sense gain via DRVL-to-PGND resistor (e.g., 11–13 V/V with no resistor). Thermal shutdown triggers at 155°C with 15°C hysteresis.

Key Specifications

Pinout & Package

ADP1872ARMZ-1.0-R7 is housed in a 10-lead MSOP package with exposed pad for thermal enhancement. Pin assignments are validated per Analog Devices Rev. B datasheet Figure 3 and Table 4.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck controller applications.

Compared with MP2315DJ-LF-Z and TPS54620RGYR, the ADP1872ARMZ-1.0-R7 uniquely combines 1.0 MHz operation, valley current-mode control, integrated bootstrap diode, and resistor-programmable current sensing - making it the only option among the three capable of stable, high-density 16 V → 0.8 V conversion without external components or performance trade-offs.

Availability

ADP1872ARMZ-1.0-R7 is available at Aetrix Electronics and suitable for telecom infrastructure, DSP core power, and mid-range server VRM applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across temperature extremes.

Supply support for ADP1872ARMZ-1.0-R7 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The ADP1872 product line delivers high-frequency synchronous buck controllers optimized for point-of-load regulation in telecom, server, and embedded systems - emphasizing transient response, efficiency at light loads, and design flexibility through programmable current sensing.

FAQ

What is the minimum input voltage supported by the ADP1872ARMZ-1.0-R7?

The ADP1872ARMZ-1.0-R7 requires a minimum bias supply (VDD) of 3.0 V, as specified in Table 1 for the 1.0 MHz variant. Its high-side input (VIN) can operate down to 3.0 V under the same condition, ensuring reliable startup and regulation in brownout scenarios common in distributed power architectures. This is distinct from the 300 kHz and 600 kHz variants, which support 2.75 V minimum.

Does the ADP1872ARMZ-1.0-R7 require an external current-sense resistor?

No, the ADP1872ARMZ-1.0-R7 does not require an external current-sense resistor. It implements low-side MOSFET R_DS(on)-based current sensing, with gain set by a resistor from DRVL to PGND (or omitted for default 12 V/V). This eliminates power loss and board space associated with shunt resistors - a key advantage confirmed in the General Description and Table 1 "Current-Sense Amplifier Gain" section.

Can the ADP1872ARMZ-1.0-R7 start up into a precharged output capacitor?

Yes, the ADP1872ARMZ-1.0-R7 supports startup into a precharged output. Its integrated soft-start circuitry prevents reverse current flow during initial turn-on, as explicitly stated in the General Description: "an internally fixed, soft start period is included [...] to provide reverse current protection during soft start for a pre-charged output." This is essential for hot-swap and redundant power systems.

What is the purpose of the BST pin on the ADP1872ARMZ-1.0-R7?

The BST pin on the ADP1872ARMZ-1.0-R7 provides the floating supply for the high-side gate driver. An internal diode connects VDD to BST, and an external capacitor between BST and SW generates the boosted voltage needed to fully enhance the upper N-channel MOSFET. As described in Table 4, this integrated bootstrap diode eliminates the need for an external Schottky diode in most designs.

How does the ADP1872ARMZ-1.0-R7 achieve stable operation at low duty cycles?

The ADP1872ARMZ-1.0-R7 achieves stable low-duty-cycle operation via its valley current-mode control architecture - a feature explicitly cited in the General Description as enabling regulation "as low as 0.6 V" with all-N-channel MOSFETs. This architecture avoids subharmonic oscillation inherent in peak current-mode control at duty cycles below 50%, confirmed by its 60 ns minimum on-time specification at 1.0 MHz.