PCA9306DQER Datasheet, PDF (9/22 Pages) Texas Instruments – DUAL BIDIRECTIONAL I2C BUS AND SMBus VOLTAGE-LEVEL TRANSLATOR

PCA9306
www.ti.com
SCPS113J – OCTOBER 2004 – REVISED OCTOBER 2010
Sizing Pullup Resistor
The pullup resistor value needs to limit the current through the pass transistor, when it is in the on state, to about
15 mA. This ensures a pass voltage of 260 mV to 350 mV. If the current through the pass transistor is higher
than 15 mA, the pass voltage also is higher in the on state. To set the current through each pass transistor at 15
mA, the pullup resistor value is calculated as:
R_PU
+
V_DPU * 0.35
0.015 A
V
The following table summarizes resistor values, reference voltages, and currents at 15 mA, 10 mA, and 3 mA.
The resistor value shown in the +10% column (or a larger value) should be used to ensure that the pass voltage
of the transistor is 350 mV or less. The external driver must be able to sink the total current from the resistors on
both sides of the PCA9306 device at 0.175 V, although the 15 mA applies only to current flowing through the
PCA9306 device.
V_DPU
5V
3.3 V
2.5 V
1.8 V
1.5 V
1.2 V
15 mA
NOMINAL
310
197
143
97
77
57
PULLUP RESISTOR VALUES ^{(1) (2)}
PULLUP RESISTOR VALUE (Ω)
+10% ⁽³⁾
10 mA
NOMINAL
+10% ⁽³⁾
341
465
512
217
295
325
158
215
237
106
145
160
85
115
127
63
85
94
(1) Calculated for V_OL = 0.35 V
(2) Assumes output driver V_OL = 0.175 V at stated current
(3) +10% to compensate for V_DD range and resistor tolerance
NOMINAL
1550
983
717
483
383
283
3 mA
+10% ⁽³⁾
1705
1082
788
532
422
312
PCA9306 Bandwidth
The maximum frequency of the PCA9306 is dependent on the application. The device can operate at speeds of
> 100MHz given the correct conditions. The maximum frequency is dependent upon the loading of the
application. The PCA9306 behaves like a standard switch where the bandwidth of the device is dictated by the
on resistance and on capacitance of the device.
Figure 4 shows a bandwidth measurement of the PCA9306 using a two-port network analyzer.
0
–1
–2
–3
–4
–5
–6
–7
–8
–9
0.1
1
10
100
1000
Frequency (MHz)
Figure 4. Bandwidth
Copyright © 2004–2010, Texas Instruments Incorporated
Product Folder Link(s): PCA9306
Submit Documentation Feedback
9