LP5524 Datasheet, PDF (4/14 Pages) National Semiconductor (TI) – Parallel LED Driver with PWM Brightness Control in Micro SMD Package

LP5524
SNVS500 – JULY 2007
www.ti.com
Electrical Characteristics ^{(1) (2)}
Limits in standard typeface are for T_J = 25°C. Limits in boldface type apply over the operating ambient temperature range (-
40°C < T_A < +85°C). Unless otherwise noted, specifications apply to the LP5524 Block Diagram with: V_IN = 3.6V, R_ISET = 32.4
kΩ, C_IN = 100 nF.
Symbol
Parameter
Condition
Min
Typ
Max
Units
I_VIN
Shutdown Supply ENA = ENB = 0V
Current
0.2
1
µA
Active Mode
Supply Current
ENA = ENB = H,
ISET = open
170
210
µA
I_DX
Recommended
3
LED Current
25
mA
I_OUT
LED Output
I_DX = 5mA, V_DX =
Current Accuracy V_IN - 0.2V
ISET = open
0.5
5
%
I_MATCH
LED Output
Current Accuracy
LED Current
Matching ⁽³⁾
I_DX = 15.9mA, V_DX
= V_IN - 0.2V
I_DX = 15.9mA
0.5
4
%
0.4
2.5
%
ΔI_DX%/ΔV_IN
ΔI_DX%/ΔV_DX
V_HR
I_MIRROR
Line Regulation
Load Regulation
Minimum
Headroom
Voltage
(V_IN - V_DX) ⁽⁴⁾
External R_ISET to
LED
Current Mirroring
Ratio
V_DX < V_IN - 0.2V
I_DX set to 5 mA
I_DX set to 15 mA
1
%/V
0.4
%/V
10
mV
30
75
mV
1:416
V_ISET
ISET Reference
Voltage
1.237
V
I_ISET
ISET Pin Current
2.5
Range
62.5
µA
t_{PWM MIN}
Recommended
Minimum
On Time For
PWM Signal
33
μs
V_IL
Logic Input Low
Level
0.4
V
V_IH
Logic Input High
1.2
V
Level
I_IN
CTRL Input
ENA / ENB = 1.2V
Current
1.2
1.9
µA
t_SD
Shutdown Delay Delay from ENA
Time
and ENB = low to
I_DX = 0.1 x I_DX
nom
20
25
µs
(1) All voltages are with respect to the potential at the GND pin.
(2) Min and Max limits are guaranteed by design, test, or statistical analysis. Typical numbers are not guaranteed, but do represent the
most likely norm.
(3) Matching is the maximum difference from the average.
(4) The current source is connected internally between V_IN an V_DX. The voltage across the current source, (V_IN - V_DX), is referred to a
Headroom Voltage (V_HR). Minimum Headroom Voltage is defined as the V_HR voltage when the LED current has dropped 20% from the
value measured at V_DX = V_IN - 1V.
4
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