Datasheet
I
(AUX)
− Auxiliary Current − mA
175
200
225
250
275
300
325
0 200 400 600 800 1000
I
(LIMIT)
− USB Current Limit − mA
G012
R
L
= 100 kΩ
T
J
= 25°C
V
IN
= 2.4 V
V
IN
= 3.3 V
V
IN
= 5.2 V
V
IN
= 4.75 V
V
IN
− Input Voltage − V
1250
1275
1300
1325
1350
1375
1400
1425
1450
3.25 3.75 4.25 4.75 5.25
I
(LIMIT)
− USB Current Limit − mA
G013
R
L
= 20 kΩ
T
J
= 25°C
I
(AUX)
= 200 mA
I
(AUX)
= 500 mA
I
(AUX)
= 0 mA
I
(AUX)
= 400 mA
I
(AUX)
= 300 mA
V
IN
− Input Voltage − V
625
650
675
700
725
750
2.25 2.75 3.25 3.75 4.25 4.75 5.25
I
(LIMIT)
− USB Current Limit − mA
G014
R
L
= 40 kΩ
T
J
= 25°C
I
(AUX)
= 500 mA
I
(AUX)
= 400 mA
I
(AUX)
= 300 mA
I
(AUX)
= 0 mA
I
(AUX)
= 200 mA
V
IN
− Input Voltage − V
175
200
225
250
275
300
325
2.25 2.75 3.25 3.75 4.25 4.75 5.25
I
(LIMIT)
− USB Current Limit − mA
G015
I
(AUX)
= 600 mA
I
(AUX)
= 500 mA
I
(AUX)
= 800 mA
I
(AUX)
= 1000 mA
I
(AUX)
= 0 mA
I
(AUX)
= 900 mA
I
(AUX)
= 700 mA
R
L
= 100 kΩ
T
J
= 25°C
I
(AUX)
= 200 mA
I
(AUX)
= 400 mA
I
(AUX)
= 300 mA
TPS2500, TPS2501
SLVS886C –OCTOBER 2008–REVISED AUGUST 2010
www.ti.com
Figure 16. USB Current-Limit Threshold vs I
AUX,
Figure 17. USB Current-Limit Threshold vs V
IN
,
R
ILIM
= 100 kΩ, T
A
= 25 °C R
ILIM
= 20 kΩ, T
A
= 25 °C
Figure 18. USB Current-Limit Threshold vs V
IN
, Figure 19. USB Current-Limit Threshold vs V
IN
,
R
ILIM
= 40 kΩ, T
A
= 25 °C R
ILIM
= 100 kΩ, T
A
= 25 °C
Accounting for Resistor Tolerance in the USB Switch Current-Limit Accuracy
The previous sections described the selection of R
ILIM
, given certain application requirements and the importance
of understanding the current-limit threshold tolerance. The analysis focused only on the TPS2500 performance
and assumed an exact resistor value. However, resistors sold in quantity are not exact and are bounded by an
upper and lower tolerance centered around a nominal resistance. The additional R
ILIM
resistance tolerance
directly affects the current-limit threshold accuracy at a system level. Table 3 shows a process that accounts for
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