Monolithic Power Systems Inc. MP4835AGRD-T

Overview

MP4835AGRD-T from Monolithic Power Systems is a 32-channel, high-voltage SPST analog switch with integrated output bleed resistors, designed for medical ultrasound transmit/receive multiplexing. It handles ±100V analog signals, supports ±1.8A peak switch current, and operates from 3.3V/5.0V supplies-no external HV rails required. Used in beamforming front-ends to route high-voltage pulses to piezoelectric transducers (PZTs) and echo signals back to receivers.

For engineers reviewing the MP4835AGRD-T datasheet, MP4835AGRD-T pinout, MP4835AGRD-T application, or MP4835AGRD-T equivalent, key selection criteria include off-isolation (-66dB @ 5MHz), 14Ω typical on-resistance, 60MHz max clock frequency, QFN-72 package thermal performance (θJA = 15°C/W), and cascaded serial control architecture for scalable channel count.

Technical Context

The MP4835AGRD-T implements a dual-stage logic interface: a 32-bit serial shift register followed by a parallel 32-bit latch, controlled via CLK, DIN, LEB, and MODE pins. Its patented level-shifting architecture enables ±100V signal switching without dedicated high-voltage supplies-only VDD (4.5–5.5V) and VLL (2.7–5.5V) are needed.

Each of the 32 independent SWIN/SWOUT channels features integrated 30kΩ bleed resistors (typical), 2.0µs turn-on/off time, and 20V/ns slew rate capability. Off-isolation (-66dB @ 5MHz) and crosstalk (-60dB @ 5MHz) are specified under 50Ω load conditions, confirming suitability for high-fidelity ultrasound echo path integrity.

Key Specifications

Pinout & Package

MP4835AGRD-T is housed in a thermally enhanced QFN-72 (10mm × 10mm) package with exposed center DAP connected to GND. The layout supports high-density ultrasound probe interface routing and efficient heat dissipation across multiple devices in stacked configurations.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage analog switch applications.

Compared with TSM1032-32QFN and ADG5436BRUZ, MP4835AGRD-T uniquely combines ±100V capability, integrated bleed resistors, 32-channel density, and daisy-chain control-enabling compact, high-fidelity ultrasound front-ends without HV supply overhead or external discharge components.

Availability

MP4835AGRD-T is available at Aetrix Electronics and suitable for medical ultrasound imaging systems, non-destructive testing equipment, and high-frequency acoustic imaging platforms requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for MP4835AGRD-T 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance power management and analog ICs, with focus on efficiency, integration, and reliability for demanding applications.

The MP4835A belongs to MPS's high-voltage analog switch product line, engineered specifically for medical ultrasound and NDT beamforming-where eliminating external HV supplies, ensuring PZT-safe discharge, and enabling scalable channel counts are primary design objectives.

FAQ

What is the maximum allowable analog signal voltage for MP4835AGRD-T?

The absolute maximum analog signal range is ±105V, but the recommended operating range is 0V to ±100V per SWIN pin. Exceeding ±100V risks degradation of off-isolation and switch lifetime, especially under repetitive high-current pulsing. Operation within ±100V ensures guaranteed -66dB off-isolation at 5MHz and 14Ω on-resistance stability across temperature.

How does the MODE pin affect control behavior?

When MODE = low, DIN serves as serial data input to the 32-bit shift register, enabling individual channel control. When MODE = high, DIN becomes a global on/off command: logic high turns all 32 switches on, logic low turns them all off. This dual-mode operation supports both fine-grained beamforming and rapid system-wide reset without firmware reconfiguration.

Can MP4835AGRD-T be used with 3.3V logic supplies?

Yes-VLL accepts 2.7V to 5.5V, so 3.3V is fully supported. At 3.3V, the maximum clock frequency drops to 30MHz (vs. 60MHz at 5.0V), and logic thresholds scale accordingly (VIL = 0.66V, VIH = 2.64V). All timing parameters-including tSU, tH, and tWLE_BAR-remain valid, and quiescent current increases slightly to 8mA average dynamic ILL.

Why is the center DAP required to connect to GND?

The exposed center DAP is electrically tied to the internal die substrate and serves as the primary thermal and electrical reference path. External connection to a low-impedance GND plane is mandatory to achieve θJA = 15°C/W and prevent junction overheating above 125°C under full 32-channel switching. Failure to connect DAP to GND degrades thermal performance by >40% and may trigger internal thermal shutdown.

What is the purpose of the integrated output bleed resistor?

The 30kΩ (typ) bleed resistor between each SWOUT pin and GND safely discharges residual voltage on the PZT element after transmit pulses, preventing mechanical ring-down and acoustic artifacts in subsequent receive cycles. This eliminates need for external RC networks, reduces PCB footprint, and ensures consistent echo baseline recovery-critical for time-of-flight accuracy in ultrasound imaging.

Does MP4835AGRD-T support simultaneous switching of all 32 channels?

Yes-when MODE = high, a single DIN transition toggles all 32 switches synchronously with <2.0µs propagation delay. In MODE = low mode, all channels update simultaneously upon LEB assertion after shift register loading, achieving deterministic, jitter-free switching across the entire array-essential for coherent beamforming and harmonic imaging.

How is daisy-chaining implemented across multiple MP4835AGRD-T devices?

Daisy-chaining uses the DOUT pin of one device connected to the DIN pin of the next. With shared CLK and LEB, a 192-channel system (six devices) loads data serially: first 32 bits go to U1, next 32 to U2, etc. After 192 clocks, LEB strobe transfers all data to latches simultaneously-ensuring atomic, glitch-free channel reconfiguration across the full array.