adg3241bryz-reel7 Analog Devices, Inc., adg3241bryz-reel7 Datasheet - Page 12

• Manufacturer Part Number: adg3241bryz-reel7
• Description: 2.5 V/3.3 V, 1-bit, 2-port Level Translator Bus Switch In Sot-66
• Manufacturer: Analog Devices, Inc.

ADG3241
BUS SWITCH APPLICATIONS
MIXED VOLTAGE OPERATION, LEVEL
TRANSLATION
Bus switches can provide an ideal solution for interfacing
between mixed voltage systems. The ADG3241 is suitable for
applications where voltage translation from 3.3 V technology to
a lower voltage technology is needed. This device can translate
from 3.3 V to 1.8 V, from 2.5 V to 1.8 V, or bidirectionally from
3.3 V directly to 2.5 V.
Figure 27 shows a block diagram of a typical application in
which a user needs to interface between a 3.3 V ADC and a
2.5 V microprocessor. The microprocessor may not have 3.3 V
tolerant inputs, therefore placing the ADG3241 between the
two devices allows the devices to communicate easily. The bus
switch directly connects the two blocks, thus introducing
minimal propagation delay, timing skew, or noise.
3.3 V TO 2.5 V TRANSLATION
When V
0 V to V
within a voltage threshold below the V
In this case, the output is limited to 2.5 V, as shown in Figure 29.
This device can be used for translation from 2.5 V to 3.3 V
devices and also between two 3.3 V devices.
Figure 27. Level Translation Between a 3.3 V ADC and a 2.5 V Microprocessor
CC
CC
3.3V ADC
Figure 28. 3.3 V to 2.5 V Voltage Translation, SEL = V
Figure 29. 3.3 V to 2.5 V Voltage Translation, SEL = V
3.3V
2.5V
, the maximum output signal will be clamped to
3.3V
is 3.3 V ( SEL = 3.3 V) and the input signal range is
2.5V
V
0V
OUT
ADG3241
SWITCH
3.3V
INPUT
3.3V
3.3V SUPPLY
SEL = 3.3V
3.3V
CC
MICROPROCESSOR
supply.
V
IN
2.5V
2.5V
2.5V
2.5V
CC
CC
Rev. B | Page 12 of 16
2.5 V TO 1.8 V TRANSLATION
When V
0 V to V
within a voltage threshold below the V
output is limited to approximately 1.8 V, as shown in Figure 31.
3.3 V TO 1.8 V TRANSLATION
The ADG3241 offers the option of interfacing between a 3.3 V
device and a 1.8 V device. This is possible through the use of
the SEL pin. The SEL pin is an active low control pin. SEL
activates internal circuitry in the ADG3241 that allows voltage
translation between 3.3 V devices and 1.8 V devices.
When V
the maximum output signal is clamped to 1.8 V, as shown in
Figure 32. To do this, the SEL pin must be tied to Logic 0. If
SEL is unused, it should be tied directly to V
Figure 30. 2.5 V to 1.8 V Voltage Translation, SEL = 2.5 V
CC
CC
CC
Figure 31. 2.5 V to 1.8 V Voltage Translation, SEL = V
Figure 32. 3.3 V to 1.8 V Voltage Translation, SEL = 0 V
2.5V
3.3V
, the maximum output signal is, as before, clamped to
is 2.5 V ( SEL = 2.5 V) and the input signal range is
is 3.3 V and the input signal range is 0 V to V
1.8V
V
0V
OUT
ADG3241
ADG3241
SWITCH
INPUT
3.3V
2.5V
2.5V SUPPLY
SEL = 2.5V
2.5V
CC
supply. In this case, the
V
IN
CC
.
1.8V
1.8V
CC
CC
CC
,