TYPICAL APPLICATIONS
OUTPUT CURRENT MONITORING
Figure 12 shows the CSR0 tolerance in function to 3
previous listed contributors in comparison to the minimum
and maximum specified values.
The main contributor is the manufacturing deviation, as
described in Figure 14. At 15 A of output current, the
tolerance will be about 8.5% versus 10% when all
contributors are considered.
Current Recopy at Vbat=9V/16V from -40°C to
125°C
Current Recopy at Vbat=9V at 25°C
24000
Spec_max
24000
23000
Spec_max
Max(Data_9V) at 6 sigmas
23000
22000
Max(Data) at 6 sigmas
Max(Data_16V) at 6 sigmas
22000
10%
21000
8.5%
Average (Data)
21000
20000
Average (Data)
Min(Data_16V) at 6 sigmas
Min(Data_9V) at 6 sigmas
19000
20000
19000
Min(Data) at 6 sigmas
18000
Spec_min
18000
17000
16000
Spec_min
17000
16000
10
15
20
25
Output current (A)
10
15
20
25
Output current (A)
Figure 12. CSR0 Ratio Deviation in Function All
Contributors
Figure 14. CSR0 Ratio Deviation in Function
Manufacturing
Lower VPWR Voltage causes more error. 9.0 V
corresponding to the worst case. Figure 13 shows the CSR0
tolerance without battery variation effect.
PART CALIBRATION
With a calibration strategy, the part to part contribution can
be removed.
An experiment was done on low output current values
(below 5.0 A). The relative CSR0 deviation based on only
one calibration point per output (5.0 A, VPWR=16 V at 25°C)
has been performed on 3 production lots. Those parts have
tested at initial and after High Temperature Operating Life
test in order to take into account the ageing of devices.
Current Recopy at Vbat=9V from -40°C to 125°C
24000
23000
22000
21000
20000
19000
18000
17000
16000
Table 19 summaries test results covering 99.74% of parts.
Table 19. CSR0 Precision for Several Output Current
Values with One Calibration Point at 5.0 A
CSR0 ratio
0.5 A
Min
Max
-25%
-12%
-8.0%
-5.0%
25%
12%
8.0%
5.0%
1.0 A
2.5 A
10
15
20
25
Output current (A)
5.0 A
Figure 13. CSR0 Ratio Deviation in Function
Manufacturing and Temperature
33984
Analog Integrated Circuit Device Data
Freescale Semiconductor
30
FREESCALE [ Freescale ]
