SSD1859 Solomon Systech, SSD1859 Datasheet - Page 44

• Manufacturer Part Number: SSD1859
• Description: 128 x 80 STN LCD Segment / Common 4 G/S Drive
• Manufacturer: Solomon Systech

OTP Programming Circuit and Sequence
OTP (One Time Programming) is a method to adjust the VOUT. In order to eliminate the variations of
LCD module in term of contrast level, OTP can be used to achieve the best contrast of every LCD
modules.
OTP setting and programming should include two major steps of (1) Find the OTP offset and (2) OTP
programming as following,
Step 1. Find the OTP offset
Step 2. OTP programming
Solomon Systech
Example 2:
(1) Hardware Reset (sending an active low reset pulse to
(2) Send original initialization routines
(3) Set and display any test patterns
(4) Adjust the contrast value (0x81, 0x00~0x3F) until there is the best visual contrast
(5) OTP setting steps = Contrast value of the best visual contrast - Contrast value of original
Example 1:
(6) Hardware Reset (sending an active low reset pulse to
(7) Enable Oscillator (0xAB)
(8) Connect an external VOUT (see diagram below)
(9) Send OTP setting commands that we find in step 1 (0x82, 0xF0~0xFF)
(10) Send OTP programming command (0x83)
(11) Wait at least 2 seconds
(12) Hardware Reset
Verify the result by repeating step 1. (2) – (3)
initialization
Contrast value of original initialization = 0x20
Contrast value of the best visual contrast = 0x24
OTP setting steps = 0x24 - 0x20 = +4
OTP setting commands should be (0x82, 0xF4)
Contrast value of original initialization = 0x20
Contrast value of the best visual contrast = 0x1B
OTP setting steps = 0x1B - 0x20 = -5
OTP setting commands should be (0x82, 0xFB)
SSD1859
VOUT
RES
GND
+
C
OTP Programming Circuit
(1) & (6) & (12)
(8)
Note: R = 1K ~ 10k ohm
R
Dec 2003
RES pin)
RES pin)
C = 1u ~ 4.7u F
P 44/48 Rev 1.0
GND
16-18V
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SSD1859