DS3514T+TR MAXIM [Maxim Integrated Products], DS3514T+TR Datasheet - Page 12

• Manufacturer Part Number: DS3514T+TR
• Description: I2C Gamma and VCOM Buffer with EEPROM
• Manufacturer: MAXIM [Maxim Integrated Products]

Map , the Latch A registers for each channel are
accessed through memory addresses 00–1Ch. Then,
like the other modes, the LD pin determines when the
DACs are updated. If the LD signal is high, Latch B is
flow-through and the DAC is updated immediately. If
LD is low, Latch B is loaded from Latch A after a low-to-
high transition on the LD pin. This latter method allows
the timing of the DAC update to be controlled by an
external signal pulse.
As illustrated in the Block Diagram , the gamma channel
outputs are equivalent to a 10-bit digital potentiometer
(DAC) with a buffered output. The V
equivalent to an 8-bit digital potentiometer (DAC) with a
I
Table 3a. V
Relationship for Selected Codes
Table 3b. Gamma DAC Voltage/Data Relationship for Selected Codes
12
2
SETTING
SETTING
(HEX)
C Gamma and V
(HEX)
______________________________________________________________________________________
3FDh
FDh
000h
001h
002h
003h
00Fh
03Fh
07Fh
0FFh
3FEh
3FFh
00h
01h
02h
03h
0Fh
3Fh
7Fh
FEh
FFh
COM
V
COM
DAC Voltage/Data
VRL + (127/255) x (VRH - VRL)
VRL + (253/255) x (VRH - VRL)
VRL + (254/255) x (VRH - VRL)
VRL + (15/255) x (VRH - VRL)
VRL + (63/255) x (VRH - VRL)
/Gamma Channel Outputs
VRL + (1/255) x (VRH - VRL)
VRL + (2/255) x (VRH - VRL)
VRL + (3/255) x (VRH - VRL)
GLM + (1021 + 1) x ((GLL - GLM)/1024)
GLM + (1022 + 1) x ((GLL - GLM)/1024)
GLM + (127 + 1) x ((GLL - GLM)/1024)
GLM + (255 + 1) x ((GLL - GLM)/1024)
V
GLM + (15 + 1) x ((GLL - GLM)/1024)
GLM + (63 + 1) x ((GLL - GLM)/1024)
GLM + (0 + 1) x ((GLL - GLM)/1024)
GLM + (1 + 1) x ((GLL - GLM)/1024)
GLM + (2 + 1) x ((GLL - GLM)/1024)
GLM + (3 + 1) x ((GLL - GLM)/1024)
COM
GM1–GM7 OUTPUT VOLTAGE
OUTPUT VOLTAGE
VRH
VRL
GLL
COM
COM
channel is
Buffer with EEPROM
buffered output. The V
tiometer is composed of 255 equal resistive elements.
The relationship between output voltage and DAC set-
ting is illustrated in Table 3a. Unlike the gamma chan-
nels, the V
range of voltages including both references (VRH and
VRL). Each of the gamma channel digital potentiome-
ters, on the other hand, are composed of 1024 equal
resistive elements. The extra resistive element prohibits
one of the rails from being reached. In particular,
gamma channel outputs GM1–GM7 can span from
(and including) GLL to 1 LSB away from GLM.
Likewise, gamma channel outputs GM8–GM14 span
from (and including) GHM to 1 LSB away from GHH.
The relationship between output voltage and DAC set-
ting for the gamma channels are also illustrated in
Table 3b.
Standby mode (not to be confused with the three
DS3514 operating modes) can be used to minimize
current consumption. Standby mode is entered by set-
ting the STANDBY bit, which is the MSB of register 41h.
The V
impedance state. Current drawn from the V
this state is specified as I
The DS3514 continues to respond to I
and thus draws some current from V
ty is occurring. When the I
rent drawn from the V
As a safety feature, the DS3514 goes into a thermal
shutdown state if the junction temperature ever reaches
COM
and gamma outputs are placed in a high-
COM
GHM + (1021 + 1) x ((GHH - GHM)/1024)
GHM + (1022 + 1) x ((GHH - GHM)/1024)
GHM + (127 + 1) x ((GHH - GHM)/1024)
GHM + (255 + 1) x ((GHH - GHM)/1024)
GHM + (15 + 1) x ((GHH - GHM)/1024)
GHM + (63 + 1) x ((GHH - GHM)/1024)
GHM + (0 + 1) x ((GHH - GHM)/1024)
GHM + (1 + 1) x ((GHH - GHM)/1024)
GHM + (2 + 1) x ((GHH - GHM)/1024)
GHM + (3 + 1) x ((GHH - GHM)/1024)
GM8–GM14 OUTPUT VOLTAGE
channel is capable of outputting a
CC
COM
supply is specified as I
DDQ
2
C interface is inactive, cur-
GHH
.
channel’s digital poten-
Thermal Shutdown
CC
Standby Mode
when I
2
C commands,
DD
2
supply in
C activi-
CCQ
.