LP3952 Datasheet, PDF (18/44 Pages) National Semiconductor (TI) – 6-Channel Color LED Driver with Audio Synchronization

AUDIO SYNCHRONIZATION ELECTRICAL PARAMETERS
Symbol
Z_IN
A_IN
f_3dB
Parameter
Input Impedance of ASE
Audio Input Level Range
(peak-to-peak)
Crossover Frequencies (-3 dB)
Narrow Frequency Response
Wide Frequency Response
Conditions
Gain = 21 dB
Gain = 0 dB
Low Pass
Band Pass
High Pass
Low Pass
Band Pass
High Pass
Min
Typical
Max
250
500
0.1
V_DDA-0.1
0.5
1.0 and 1.5
2.0
1.0
2.0 and 3.0
4.0
CONTROL OF ADC AND AUDIO SYNCHRONIZATION
The following table describes the controls required for audio synchronization.
GAIN_SEL[2:0]
SYNC_MODE
EN_AGC
EN_SYNC
INPUT_SEL[1:0]
EN_AVG
MODE_CTRL[1:0]
SPEED_CTRL[1:0]
Audio_sync_CTRL1 (2AH)
Input signal gain control. Range 0...21 dB, step 3 dB:
Bits 7-5 ^{[000] = 0 dB (default)}
[001] = 3 dB
[011] = 9 dB
[100] = 12 dB
[110] = 18 dB
[111] = 21 dB
[010] = 6 dB
[101] = 15 dB
Synchronization mode selector.
Bit 4 SYNCMODE = 0 → Amplitude Mode (default)
SYNCMODE = 1 → Frequency Mode
Bit 3
Automatic Gain Control enable
1 = enabled
0 = disabled (Gain Select enabled) (default)
Bit 2
Audio synchronization enable
1 = Enabled
Note : If AGC is enabled, AGC gain starts from current GAIN_SEL gain value.
0 = Disabled (default)
Bits 1-0
[00] = Single ended input signal, ASE.
[01] = Not used
[10] = Not used
[11] = No input (default)
Audio_sync_CTRL2 (2BH)
Bit 4
0 – averaging disabled (not applicable in audio sync mode)
1 – averaging enabled (not applicable in audio sync mode)
Bits 3-2 See below: Mode control
Bits 1-0
Sets the LEDs light response time to audio input.
[00] = FASTEST (default)
[01] = FAST
[10] = MEDIUM
[11] = SLOW
(For SLOW setting in amplitude mode f_MAX= 3.8 Hz,
Frequency mode f_MAX = 7.6 Hz)
Units
kΩ
V
kHz
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