
19
Maxim Integrated
Dual Automotive, Audio Line Drivers
with I2C Control and Diagnostic
MAX13325/MAX13326
Figure 7. A Single-Byte Read Operation
Figure 8. A Burst Read Operation
Charge Pump
The MAX13325/MAX13326 charge pump can be dis-
abled depending on application requirements. When
charge pump is enabled [CPOFF = 0], please follow the
charge-pump capacitor selections. When the charge
pump is disabled [CPOFF = 1], the flying capacitor
(C1) is not needed. There are internal diodes between
VDD/OUT_ to CHOLD, so it is important that CHOLD
not be forced below VDD or any of the outputs. A series
diode needs to be placed between the external supply
(VSUP) and CHOLD. See D2 in the Typical Operating
Circuit.
Charge-Pump Capacitor Selection
Use ceramic capacitors with a low ESR for optimum per-
formance. For optimal performance over the extended
temperature range, select capacitors with an X7R
dielectric. Table 19 lists suggested manufacturers.
Flying Capacitor (C1)
The value of the flying capacitor (see the Typical
Operating Circuit) affects the charge pump’s load regu-
lation and output resistance. A C1 value that is too small
degrades the device’s ability to provide sufficient current
drive, which leads to a loss of output voltage. Increasing
the value of C1 improves load regulation and reduces
the charge-pump output resistance. For optimum perfor-
mance, use a 470nF capacitor for C1. When the charge
pump is disabled [CPOFF = 1], the flying capacitor (C1)
is not needed.
Hold Capacitor (C2)
The hold capacitor value (see the Typical Operating
Circuit) and ESR directly affect the ripple at the internal
negative rail. Increasing the value of C2 reduces output
ripple. Likewise, decreasing the ESR of C2 reduces both
ripple and output resistance. Lower capacitance values
can be used in systems with low maximum output power
levels. For optimum performance, use a 1FF capacitor
for C2.
Table 19. Suggested Capacitor Vendors
S
S7
S6
S5
S4
S3
S2
S1
ACK
B7
B6
B5
B4
B3
B2
B1
B0
ACK
SLAVE ADDRESS
REGISTER ADDRESS
R/W
= 0
Sr
S7
S6
S5
S4
S3
S2
S1
ACK
B7
B6
B5
B4
B3
B2
B1
B0 NACK
P
SLAVE ADDRESS
DATA
R/W
= 1
S
S7
S6
S5
S4
S3
S2
S1
ACK
B7
B6
B5
B4
B3
B2
B1
B0
ACK
SLAVE ADDRESS
REGISTER ADDRESS
R/W
= 0
Sr
S7
S6
S5
S4
S3
S2
S1
ACK
B7
B6
B5
B4
B3
B2
B1
B0
ACK
SLAVE ADDRESS
DATA 1
R/W
= 1
ACK
B7
B6
B5
B4
B3
B2
B1
B0 NACK
P
DATA N
SUPPLIER
PHONE
FAX
WEBSITE
Murata Electronics North America, Inc.
770-436-1300
770-436-3030
www.murata-northamerica.com
Taiyo Yuden
800-348-2496
847-925-0899
www.t-yuden.com
TDK Corp.
847-803-6100
847-390-4405
www.component.tdk.com