Datasheet

A-port
4 kΩ
4 kΩ
One-
shot
Translator
V
CCA
V
CCB
B-port
T
1
T
2
T
3
T
4
Translator
One-
shot
One-
shot
One-
shot
1.8 V
3.3 V
4 kΩ
V = 3.3 V
CCB
Output
B-Port
One-
shot
1.8 V
3.3 V
Input
signal
Output
signal
4 kΩ
Output
B-Port
Time ns
T
2
V = 3.3 V
CCB
One-
shot
One-
shot
One-
shot
Input
signal
Output
signal
Time ns
T
2
T
1
T
1
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Auto-Direction Sensing Voltage Translator Architecture
Figure 2. Basic TXB010x Architecture
The TXB translators incorporate a weak buffer with one-shot (O.S.) circuitry to improve switching speeds
for rising and falling edges. When the A-port is connected to a system driver and driven high, the weak
4-kΩ buffer drives the B-port high in conjunction with the upper one shot, which becomes active when it
senses a rising edge. The B-port is driven high by both the buffer and the T
1
PMOS, which lowers the
output impedance seen on the B-port while the O.S. circuit is active. On the falling edge, the lower O.S. is
triggered and the buffer, along with the T
2
NMOS, lowers the output impedance seen on the B-port while
the O.S. circuit is operating and the output is driven low.
Figure 3 highlights with color the active circuitry involved in a low-to-high transition and a high-to-low
transition. The weak buffer is shown in blue, and the active O.S. circuit is shown in green.
Figure 3. Active Output Rising/Falling Edge-Rate Acceleration Circuitry and DC Resistor Paths
3
SCEA043March 2010 A Guide to Voltage Translation With TXB-Type Translators
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