DS3988T+T&R Maxim Integrated Products, DS3988T+T&R Datasheet - Page 18

• Manufacturer Part Number: DS3988T+T&R
• Description: Display Drivers 8-Ch CCFL Controller All N-FET Drive, La
• Manufacturer: Maxim Integrated Products

Specifications of DS3988T+T&R

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8-Channel Cold-Cathode
Fluorescent Lamp Controller
Table 4. Control Register 2 (CR2)
18
BIT
____________________________________________________________________
0
1
2
3
4
5
6
7
POSCR0
POSCR1
NAME
UMWP
LSR0
LSR1
LD0
LD1
LD2
User Memory Write Protect.
0 = User Memory Write Access Blocked
1 = User Memory Write Access Permitted
DPWM Oscillator Range Select. When using an external source for the dimming clock, these bits must
be set to match the external oscillator’s frequency. When using a resistor to set the dimming
frequency, these bits plus the external resistor control the frequency.
Lamp Sample Rate Select. Determines the feedback sample rate of the LCM inputs
Lamp Disable. Used to disable channels if all 8 are not required for an application.
LD2
0
0
0
0
1
1
1
1
POSCR1
LSR1
0
0
1
1
0
0
1
1
LD1
0
0
1
1
0
0
1
1
LD0
0
1
0
1
0
1
0
1
POSCR0
LSR0
0
1
0
1
0
1
0
1
All Channels Enabled
8
4/8
2/4/8
2/4/6/8
2/4/6/7/8
2/3/4/6/7/8
2/3/4/5/6/7/8
CHANNELS DISABLED
DIMMING CLOCK (DPWM)
FREQUENCY RANGE (Hz)
16 Lamp Frequency Cycles
32 Lamp Frequency Cycles
4 Lamp Frequency Cycles
8 Lamp Frequency Cycles
FUNCTION
SELECTED LAMP
SAMPLE RATE
22.5 to 55.0
180 to 440
45 to 110
90 to 220
EXAMPLE SAMPLE RATE
IF LAMP FREQUENCY IS
NUMBER OF ACTIVE
LAMP CHANNELS
(kΩ • kHz)
12500Hz
6250Hz
3125Hz
1563Hz
50kHZ
K
1
2
4
8
8
7
6
5
4
3
2
1