Datasheet

MAX4800A/MAX4802A
Low-Charge-Injection, 8-Channel, High-Voltage
Analog Switches with 20MHz Serial Interface
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Detailed Description
The MAX4800A/MAX4802A provide high-voltage
switching on eight channels for ultrasound imaging and
printer applications. The devices utilize BCDMOS
process technology to provide eight high-voltage low-
charge-injection SPST switches, controlled by a 20MHz
serial interface. Data is clocked into an internal 8-bit
shift register and retained by a programmable latch
with enable and clear inputs. A power-on reset function
ensures that all switches are open on power-up.
The devices operate with a wide range of high-voltage
supplies including: V
PP
/V
NN
= +100V/-100V,
+185V/-15V, or +40V/-160V. The digital interface oper-
ates from a separate V
DD
supply from +2.7V to +6V.
Digital inputs DIN, CLK, LE, and CLR are +6V tolerant,
independent of the V
DD
supply voltage. The MAX4802A
provides integrated 35kΩ bleed resistors on each
switch terminal to discharge capacitive loads.
The devices are drop-in replacements for the Supertex
HV2203 and HV2303, respectively.
Analog Switch
The devices allow a peak-to-peak analog-signal range
from V
NN
+ 10V to V
PP
- 10V. Analog switch inputs
must be unconnected, or satisfy V
NN
≤ (V
COM_
,
V
NO_
) ≤ V
PP
during power-up and power-down.
High-Voltage Supplies
The devices allow a wide range of high-voltage sup-
plies. The devices operate with V
NN
from
-160V to -15V and V
PP
from +40V to (V
NN
+ 200V).
When V
NN
is connected to GND (single-supply applica-
tions), the devices operate with V
PP
up to +200V.
50%
50%
t
WC
90%
t
ON
DIN
LE
CLK
DOUT
SWITCH
*FOR SLOWER CLK RATES REFER TO THE MAX4800/MAX4801/MAX4802 DATA SHEET.
CLR
OFF
ON
10%
t
OFF
t
DO
t
DH
t
DS
50%
50%
50%
50%
50%
50%
D
N
D
N-1
D
N+1
t
WL
t
CS
Figure 1. Serial Interface Timing*