PCA8538UG(2014) 查看數據表（PDF） - NXP Semiconductors.
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PCA8538UG Datasheet PDF : 107 Pages
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NXP Semiconductors
PCA8538
Automotive 102 x 9 Chip-On-Glass LCD segment driver
External capacitors of 100 nF minimum are required on each of the pins VDD1 to VDD3.
VDD1 to VDD3 can be connected to the same power supply. In this case, a capacitor of
300 nF minimum is required.
VSS1 to VSS3 can be connected to the same ground supply.
The VLCD pins (VLCDOUT, VLCDSENSE, VLCDIN) can be connected, whether VLCD
generated internally or supplied from external. An external capacitor of 300 nF minimum is
recommended for VLCD. For high display loads, 1 F is suggested.
8.10 LCD voltage
8.10.1 VLCD pins
The PCA8538 has 3 VLCD pins:
VLCDIN — VLCD supply input
VLCDOUT — VLCD voltage output
VLCDSENSE — VLCD regulation circuitry input
The VLCD voltage can be generated on-chip or externally supplied.
8.10.2
External VLCD supply
When the external VLCD supply is selected (CPE = 0), the VLCD voltage must be supplied
to the pin VLCDIN. The pins VLCDOUT and VLCDSENSE can be left unconnected or
alternatively connected to VLCDIN.
The internal charge pump must not be enabled, otherwise an extra current may occur on
pin VDD2 and pin VLCD. When VLCD is supplied externally, no internal temperature
compensation occurs on this voltage even if bit TCE is set logic 1 (see Section 8.10.4).
The VLCD voltage which is supplied externally will be available at the segments and
backplanes of the device through the chosen bias system. Also programming the V[8:0]
bit field has no effect on the externally supplied VLCD.
8.10.3
Internal VLCD generation
When the internal VLCD generation is selected (CPE = 1), the VLCD voltage is available on
pin VLCDOUT. The pins VLCDIN and VLCDSENSE must be connected to the pin
VLCDOUT.
VLCD can be generated by an on-chip charge pump and controlled by command (Table 15
on page 14). The VLCD voltage is available on pin VLCDOUT.
The charge pump is controlled by the Charge-pump-ctrl command (see Table 14 on
page 14). It can be enabled with the CPE bit. The multiplier setting can be configured with
the CPC[2:0] bits. The charge pump can generate a VLCD up to 5 VDD2.
8.10.3.1 VLCD programming
VLCD can be programmed by using the V[8:0] (see Table 15 on page 14).
The final value of VLCD is a combination of the programmed V[8:0] value and the output of
the temperature compensation block, VT[8:0] (see Equation 2). The system is exemplified
in Figure 14.
PCA8538
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 4 — 26 September 2014
© NXP Semiconductors N.V. 2014. All rights reserved.
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