Microchip Technology HV7321K6-G

Overview

HV7321 from Microchip Technology is a 4-channel, 5-level high-voltage ultrasound pulser IC with integrated T/R switches, RX damper, RTZ bleeder, and ±80V output swing. It delivers ±2.5A peak current per channel, achieves −44 dB HD2 at 5 MHz, supports re-timing clock up to 220 MHz, and operates in transparent or re-timing mode for FPGA-driven medical ultrasound imaging systems.

For engineers reviewing the HV7321 datasheet, HV7321 pinout, HV7321 application, or HV7321 equivalent, key selection criteria include its 5-level voltage output capability, CW-mode flexibility (Mode-0/Mode-1), ±80V rail support, integrated protection diodes/clamps, and 64-pin VQFN package thermal performance in high-power pulsed-echo systems.

Technical Context

The HV7321 implements dual high-voltage rail switching (VPP0/VNN0 and VPP1/VNN1) with independent P/N-channel MOSFET drivers per channel, enabling five discrete output levels: RTZ, VPP0, VNN0, VPP1, and VNN1. Its re-timing logic synchronizes input control signals to an external clock (10–220 MHz), reducing jitter introduced by FPGA timing uncertainty.

Two CW transmission modes are supported: Mode-0 uses internal VPP1/VNN1 rails delivering ±300 mA, while Mode-1 enables external CW waveform injection via CWIN0–CWIN3 pins through integrated analog switches (R_CWSW = 26.5 Ω typ). Integrated gate drive regulators (VPF0/VNF0 etc.) provide precise −4.6V/+4.2V referenced gate voltages for optimal FET switching under ±80V rails.

Key Specifications

Pinout & Package

The HV7321 is housed in a thermally enhanced 9 mm × 9 mm 64-lead Very Thin Quad Flat No-Lead (VQFN) package with exposed thermal pad (VSUB) requiring solder connection to PCB ground plane for optimal heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultrasound transmitter applications.

Compared with AFE5809 and AD9410, the HV7321 uniquely combines 4-channel ±80V pulsing, integrated T/R switching, dual CW modes, and RTZ bleeder functionality in a single 64-pin VQFN-reducing board area, BOM count, and timing validation effort for clinical and industrial ultrasound systems.

Availability

HV7321 is available at Aetrix Electronics and suitable for medical ultrasound imaging, NDT inspection, and piezoelectric transducer driver applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing from authorized channels.

Supply support for HV7321 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

Microchip Technology Inc. is a leading provider of microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and medical markets with high-reliability semiconductor products.

The HV7321 belongs to Microchip's high-voltage ultrasound transmitter product line, engineered specifically for precision timing, low distortion, and robust protection in diagnostic and therapeutic ultrasound systems.

FAQ

What is the maximum output voltage swing supported by the HV7321?

The HV7321 supports a maximum output voltage swing of ±80V across its VPP0/VNN0 and VPP1/VNN1 rails. Absolute maximum ratings allow ±85V transient conditions, but sustained operation must remain within ±80V to ensure reliability and stay within specified electrical characteristics. This swing enables direct excitation of high-impedance piezoelectric transducers without external level-shifting circuitry.

How does the HV7321 implement Return-to-Zero (RTZ) functionality?

The HV7321 implements true RTZ using integrated bleeder switches (RTZSW) that actively discharge TX outputs to GND with R_on = 238 Ω typ. When SEL/POS/NEG = 000, RTZSW turns on, pulling the output to 0V-not high-impedance-ensuring rapid settling before echo reception. This eliminates residual charge that could distort weak returning echoes in medical and NDT ultrasound systems.

What are the key differences between CW Mode-0 and CW Mode-1 in the HV7321?

In CW Mode-0 (MODE = 0, PWS = 0), the HV7321 uses internal VPP1/VNN1 rails to generate low-voltage CW output (±5V typical) with ±300 mA current. In CW Mode-1 (MODE = 1), it routes external CW waveforms from CWIN0–CWIN3 pins through low-R_on analog switches (26.5 Ω) to the output stage-enabling hybrid beamformers where the CW source is separate from the pulser IC.

Does the HV7321 require external gate drive supplies?

No-the HV7321 integrates linear gate drive regulators that generate precise gate voltages referenced to each high-voltage rail: VPF0/VNF0 for VPP0/VNN0 and VPF1/VNF1 for VPP1/VNN1. These regulators accept VGP = +10V and VGN = −10V inputs and deliver −4.6V/+4.2V gate drives, eliminating need for external gate drivers or isolated supplies in the HV7321 design.

What thermal management provisions does the HV7321 include?

The HV7321 includes an open-drain OTPN pin that asserts low when junction temperature exceeds 125–160°C (typ. 138°C), signaling thermal shutdown. Its 9 mm × 9 mm VQFN package features a thermal pad (VSUB) that must be soldered to a PCB ground plane. With JEDEC 4-layer board, θ_JA = 16.3°C/W and θ_JB = 2.55°C/W enable reliable operation up to 3.0 W total dissipation at 85°C ambient.