MAX14808 Datasheet, PDF (1/31 Pages) Maxim Integrated Products – Octal Three-Level/Quad Five-Level High-Voltage 2A Digital Pulsers with T/R Switch

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MAX14808 / MAX14809
Octal Three-Level/Quad Five-Level High-Voltage
2A Digital Pulsers with T/R Switch
General Description
The MAX14808/MAX14809 octal three-level/quad five-
level, high-voltage (HV) pulser devices generate high-
frequency HV bipolar pulses (up to Q105V) from low-
voltage 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 return-
to-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
500I. It fully discharges the pulser’s output internal node
before the grass-clipping diodes.
The devices are available in a 68-pin (10mm x 10mm)
TQFN package with an exposed pad and are specified
over the -40NC to +85NC extended temperature range.
Benefits and Features
S Save Space (Optimized for High-Channel-Count
Systems/Portable Systems)
 High Density
• Eight Channels (Three-Level Operation)
• Four 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
S 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
S Save Power
 Low Quiescent Power Dissipation (5.7mW/
Channel in Octal Mode)
 Programmable Current Capability
 Shutdown Mode and Disable Transmit Mode
Applications
Ultrasound Medical Imaging
Industrial Flaw Detection
Piezoelectric Drivers
Test Equipment
Ordering Information and Functional Diagram appear at end
of data sheet.
DirectDrive is a registered trademark of Maxim Integrated.
For related parts and recommended products to use with this part, refer to www.maximintegrated.com/MAX14808.related.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-6438; Rev 0; 9/12