MAX14808ETK+T

The MAX14808/MAX14809 octal three-level/quad fivelevel, high-voltage (HV) pulser devices generate highfrequency HV bipolar pulses (up to ± 105V) from lowvoltage control logic inputs for driving piezoelectric transducers in ultrasound systems. All eight channels have embedded overvoltage-protection diodes and an integrated active return-to-zero clamp. Both devices have embedded independent (floating) power supplies (FPS) and level shifters that allow signal transmission without the need for external HV capacitors. The MAX14808 also features eight integrated transmit/receive (T/R) switches. The MAX14809 does not have the T/R switch function. The devices feature two modes of operation: an octal three-level pulser mode (with integrated active returnto-zero clamp) or a quad five-level pulser mode. In octal three-level pulser mode, each channel is controlled by two logic inputs (DINN_/DINP_) and the active return to zero features half the current driving of the pulser 1A (typ). In quad five-level pulser mode, each channel is controlled by three logic inputs and the active return to zero has the same current driving of the pulser 2A (typ). The devices can operate both in clocked and transparent mode. In clocked mode, data inputs can be synchronized with a clean differential or single-ended clock to reduce phase noise associated with FPGA output signals that are detrimental for Doppler analysis. In transparent mode, the synchronization feature is disabled and output reflects the data input after a 18ns delay. Both devices feature adjustable maximum current (0.5A to 2A) to reduce power consumption when full current capability is not required. The devices feature integrated grass-clipping diodes (with low parasitic capacitance) for receive (Rx) and transmit (Tx) isolations. Both devices feature a damping circuit that can be activated as soon as the transmit burst is over. The damping circuit has a typical on-resistance of 500Ω. It fully discharges the pulser’s output internal node before the grass-clipping diodes. The devices are available in a 68-pin (10mm × 10mm) TQFN package with an exposed pad and are specified over the -40°C to +85°C extended temperature range.

Applications

• Ultrasound Medical Imaging
• Industrial Flaw Detection
• Piezoelectric Drivers
• Test Equipment

Key features

• Save Space (Optimized for High-Channel-Count Systems/Portable Systems)
• High Density
• 8 Channels (Three-Level Operation)
• 4 Channels (Five-Level Operation) in One Package
• Integrated Low-Power T/R Switches (MAX14808)
• DirectDrive Architecture Eliminates External High-Voltage Capacitor
• No External Floating Power Supply (FPS) Required
• High Performance (Designed to Enhance Image Quality)
• Excellent -43dBc (typ) THD for Second Harmonic at 5MHz
• Sync Function Eliminates Effects of FPGA Jitter and Improves Performance in Doppler Mode
• Low Propagation Delay 18ns (typ)
• Strong Active Return to Zero
• Save Power
• Low Quiescent Power Dissipation (5.7mW/ Channel in Octal Mode)
• Programmable Current Capability
• Shutdown Mode and Disable Transmit Mode