
MC34844
ELECTRICAL CHARACTERISTICS
STATIC AND DYNAMIC ELECTRICAL CHARACTERISTICS
Table 4. Static and Dynamic Electrical Characteristics (continued)
Characteristics noted under conditions V IN = 12 V, V OUT = 42 V, I LED = 50 mA, PWM = VDC1, M/~S = VDC1,
PIN & NIN = VDC1, - 40 ° C ≤ T A ≤ 105 ° C, PGND = 0 V, unless otherwise noted.
Line Regulation (9)
Characteristic
Symbol
I OUT /V IN
Min
-0.2
Typ
-
Max
0.2
Unit
%/V
VIN=7.0 to 28 V
Load Regulation (9)
I OUT /V LED
-0.2
-
0.2
%/V
VLED = 8.0 to 65 V (all Channels)
Slope compensation voltage ramp
V SLOPE
-
0.49
-
V/ μ s
R SLOPE = 68 k Ω
Current Sense Amplifier Gain
A CSA
-
9.0
-
Current Sense Resistor
OTA Transconductance
Transconductance Sink and Source Current Capability
Output Voltage Precharge
R SENSE
G M
I SS
V HOLD
-
-
-
0.45
22
200
100
0.5
-
-
-
0.55
m Ω
μ S
μ A
V
FAIL PIN
Off-state Leakage Current
I FAIL_LEAK
-
-
5
μ A
V FAIL = 5.5 V
On-state Voltage Drop
V OL
-
-
0.4
V
I SINK = 4.0 mA
LED CHANNELS
Sink Current
I SINK
49
50
51
mA
ICHx Register = 255, RISET=5.1 k Ω 0.1%, PIN&NIN = Disabled,
T A =25 °C
Regulated minimum voltage across drivers
V MIN
675
750
825
mV
Pulse Width > 4.0 μ s
Current Matching Accuracy
I SET Pin Voltage
I MATCH
V SET
-2.0
2.017
-
2.048
2.0
2.079
%
V
RISET=5.1 k Ω 0.1%
LED Current Amplitude Resolution
ILED RES
-
1.5
-
%
1.0 mA < I LED < 50 mA
Off-state Leakage Current, All channels
I CH_LEAK
-
-
10
μ A
(V CH = 45 V)
PIN INPUT
Voltage to Disable PIN mode
PIN Bias Current
V PIN_DIS
I PIN
2.2
-2.0
-
-
-
2.0
V
μ A
PIN = V SET
Analog Dimming Current
ICHx Register = 255, RISET=5.1 k Ω 0.1%
I DIM_PIN
mA
PIN = V SET /2
PIN = V SET
23.75
47.50
25
50
26.25
52.50
Notes
9. Guaranteed by design
34844
Analog Integrated Circuit Device Data
Freescale Semiconductor
10