The MAX14987 octal five-level, high-volage (HV) pulser
device generates high-frequency HV bipolar pulses (up to
±105V) 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.
The device has embedded independent (floating) power
supplies (FPS) and level shifters that allow signal
transmission without the need for external HV capacitors.
The device also features eight integrated transmit/receive
(T/R) switches.
The device features two modes of operation: shutdown
mode and octal five-level mode pulsing (with integrated
active return-to-zero clamp). In octal five-level mode
pulsing, each channel is controlled by three logic inputs
(DINN_/DINP_/SEL_). Each channel features two HV
half-bridges operating from independent pairs of voltage
supplies (VPPA, VNNA and VPPB, VNNB) and sharing the
same output. The half-bridge operating from VPPA, VNNA
is named HB1 while the half-bridge operating from VPPB,
VNNB is named HB2. The voltage rating is the same for
the two half-bridges. They can both operate from 0 to
±105V.
HB1 is sized to provide a maximum driving current in
excess of ±2.5A and is optimized in terms of Bandwidth
and PWM performances.
HB2 is sized to provide a maximum driving current of
±1.6A and is normally intended to be used in Doppler
modes (CWD, CFM, PWD). The driving current of HB2
can be programmed at 1.6A, 1.1A, 0.5A, and 0.3A. This
allows reducing the power dissipation in particular for
CWD modality. HB2 exhibits excellent jitter (< 6ps) and
phase noise performances (156dBc @1kHz offset) in
CWD modality.
The return-to-zero (clamp) driving current can also be programmed either at 1.25A or 2.5A by means of a dedicated
CMOS input (RTZ).
The device is available in a 228-bump (10mm x 16mm)
BGA package and are specified over the -40°C to +85°C
extended temperature range.
APPLICATIONS
- Ultrasound Medical Imaging
- Industrial Flaw Detection
- Piezoelectric Drivers
- Test Equipment
