pcf8535 NXP Semiconductors, pcf8535 Datasheet - Page 13

• Manufacturer Part Number: pcf8535
• Description: 65 X 133 Pixel Matrix Driver
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 6 Values for parameters of V
7.14
7.14.1
The PCF8535 incorporates a software configurable
voltage multiplier. After reset (RES) the voltage multiplier
is set to 2
via the HV-gen command page. Before switching on the
charge pump, the charge pump has to be pre-charged
using the following sequence.
A starting state of HVE = 0, DOF = 0, PD = 1 and DM = 0
is assumed. A small delay between the steps is indicated.
The recommended wait period is 20 s per 100 nF of the
capacitance on V
1. Set DM = 1 and PD = 0
2. Delay
3. Set the multiplication factor to 2 by setting S[1:0] = 00
2001 Nov 07
handbook, full pagewidth
a
b
T
cut
65
V
OP
[6:0] programming (00H to 7FH, programming range LOW and HIGH).
Voltage multiplier control
V LCD
S[1:0]
133 pixel matrix driver
SYMBOL
(V)
V
DD2
00
a
. Other voltage multiplier factors are set
LCD
01
b
.
02
03
04
LOW
05
OP
programming
06
PRS = 0
PRS = 1
Fig.5 V
BITS
. . .
7D
OP
programming of PCF8535.
7E
7F
13
00
4. Set the required V
5. Set HVE = 1 to switch-on the charge pump with a
6. Delay
7. Increase the number of stages, one at a time, with a
Table 7 HV generator multiplication factor
01
multiplication factor of 2
delay between each until the required level is
achieved.
S1
0
0
1
1
02
VALUE
10.215
0.045
4.5
03
27
04
HIGH
S0
05
0
1
0
1
OP
06
and PRS.
. . .
MULTIPLICATION FACTOR
7D
7E
Product specification
MGS472
2
3
4
5
UNIT
7F
PCF8535
V
V
V
V
V
V
V
C
DD2
DD2
DD2
DD2