LM3424 Datasheet, PDF (4/50 Pages) National Semiconductor (TI) – Constant Current N-Channel Controller with Thermal Foldback for Driving LEDs

Symbol
Parameter
Conditions
OSCILLATOR (RT)
f_SW
Switching Frequency
R_T = 36 kΩ
V_RT-SYNC
Sync Threshold
PWM COMPARATOR
R_T = 12 kΩ
V_CP-BASE
COMP to PWM Offset - No
Slope Compensation
SLOPE COMPENSATION (SLOPE)
ΔV_CP
Slope Compensation
Amplitude
Additional COMP to PWM Offset -
SLOPE sinking 100 µA
CURRENT LIMIT (IS)
V_LIM
Current Limit Threshold
V_LIM Delay to Output
t_ON-MIN
Leading Edge Blanking Time
HIGH SIDE TRANSCONDUCTANCE AMPLIFIER
Input Bias Current
Transconductance
Input Offset Current
Input Offset Voltage
Transconductance
Bandwidth
I_CSH = 100 µA (Note 9)
GATE DRIVER (GATE)
R_SRC-GATE
GATE Sourcing Resistance GATE = High
R_SNK-GATE
GATE Sinking Resistance GATE = Low
UNDER-VOLTAGE LOCKOUT and DIM INPUT (nDIM)
V_TH-nDIM
nDIM / UVLO Threshold
I_HYS-nDIM
nDIM Hysteresis Current
DIM DRIVER (DDRV)
R_SRC-DDRV
R_SNK-DDRV
DDRV Sourcing Resistance DDRV = High
DDRV Sinking Resistance DDRV = Low
nDIM rising to DDRV rising
nDIM rising to DDRV falling
SOFT-START (SS)
I_SS
Soft-start current
THERMAL CONTROL
V_S
I_TGAIN-MAX
V_S Voltage
TREF input bias current
TSENSE Input Bias Current
TGAIN Maximum Sourcing
Current
I_VS = 0A
I_VS = 1 mA
V_TREF = 1.5V
V_TSENSE = 1.5V
V_TREF = 1.5V
V_TSENSE = 1.5V
V_TGAIN = 2V
I_TF
CSH Current with High-side R_TGAIN = 10 V_TREF = 1.5V
Amplifier Disabled
kΩ
V_TSENSE = 0.5V
V_TREF = 1.5V
V_TSENSE = 1.4V
V_TREF = 1.5V
V_TSENSE = 1.5V
Min
(Note 7)
164
525
750
215
140
20
-1.5
-5
1.185
13
2.40
200
Typ
(Note 8)
207
597
3.5
900
85
245
35
240
10
0
0
500
2.0
1.3
1.240
20
13.5
3.5
700
360
10
2.45
0.1
0.1
600
100
10
2
Max
(Note 7)
250
669
1050
275
75
340
1.5
5
6.0
4.5
1.285
27
30.0
10.0
2.50
Units
kHz
V
mV
mV
mV
ns
µA
mA/V
µA
mV
kHz
Ω
V
µA
Ω
ns
µA
V
µA
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