LM3697_15 Datasheet, PDF (6/43 Pages) Texas Instruments – High-Efficiency Three-String White LED Driver

LM3697
SNOSCS2C – NOVEMBER 2013 – REVISED OCTOBER 2015
www.ti.com
6.5 Electrical Characteristics
Limits apply over the full operating ambient temperature range (−40°C ≤ T_A ≤ 85°C) and V_IN = 3.6 V, unless otherwise
specified. ^{(1) (2)}
PARAMETER
TEST CONDITIONS
MIN TYP MAX UNIT
I_SHDN
I_{LED_MIN}
T_SD
Shutdown current
Minimum LED current
Thermal shutdown
Hysteresis
2.7 V ≤ V_IN ≤ 5.5 V, HWEN = GND
T_A = 25°C
Full-scale current = 20.2 mA
Exponential Mapping, T_A = 25°C
3
µA
1
6
µA
140
°C
15
BOOST CONVERTER
I_HVLED(1/2/3)
Output current regulation
(HVLED1, HVLED2, HVLED3)
Full-scale current= 20.2 mA,
Exponential mapping,
Brightness Code = max.
2.7 V ≤ V_IN ≤ 5.5 V
Full-scale current= 20.2 mA,
Exponential mapping,
Brightness Code = max.
HVLED1 Bank A, HVLED2/3
Bank B
T_A = 25°C
T_A = 25°C
3 V ≤ V_IN ≤ 4.5 V
T_A = 25°C
18.38 20.2 22.02 mA
–3.4%
–3.6%
±2 %
±2 %
3.2%
3.4%
I_{MATCH_HV}
HVLED1 to HVLED2 or
HVLED3 matching ⁽³⁾
V_{REG_CS}
Regulated current sink
headroom voltage
Exponential mapping,
auto headroom off,
PWM Off,
HVLED1/2/3 Bank A
2.7 V ≤ V_IN ≤ 5.5 V
I_LED = 20.2 mA
T_A = 25°C
I_LED = 20.2 mA
2.7 V ≤ V_IN ≤ 5.5 V
I_LED = 500 µA
Auto-headroom off, T_A = 25°C
−2.5%
–2%
–8.5%
2.5%
1.7%
8.5%
400
mV
V_{HR_MIN}
Minimum current sink
headroom voltage for HVLED
current sinks
I_LED = 95% of nominal, Full-scale current = 20.2 mA
I_LED = 95% of nominal, Full-scale current =
20.2 mA , T_A = 25°C
275
mV
190
R_DSON
NMOS switch on resistance
I_SW = 500 mA, T_A = 25°C
0.3
Ω
I_{CL_BOOST} NMOS switch current limit
T_A = 25°C
880
1120
mA
1000
V_OVP
ON Threshold
Output overvoltage protection ^{OVP select bits = 11}
2.7 V ≤ V_IN ≤ 5.5 V
T_A = 25°C
38.75
41.1
40
V
Hysteresis
T_A = 25°C
1
ƒ_SW
Switching frequency
Boost frequency select bit =
0
Boost frequency select bit =
1
2.7 V ≤ V_IN ≤ 5.5 V
T_A = 25°C
2.7 V ≤ V_IN ≤ 5.5 V
T_A = 25°C
450
550
500
kHz
900
1100
1000
D_MAX
Maximum duty cycle
T_A = 25°C
94%
HWEN INPUT
V_{HWEN_L}
V_{HWEN_H}
Logic low
Logic high
2.7 V ≤ V_IN ≤ 5.5 V
2.7 V ≤ V_IN ≤ 5.5 V
0
0.4
V
1.2
V_IN
(1) All voltages are with respect to the potential at the GND pin.
(2) Minimum and Maximum limits are verified by design, test, or statistical analysis. Typical numbers are not verified, but do represent the
most likely norm. Unless otherwise specified, conditions for typical specifications are: V_IN = 3.6 V and T_A = 25°C.
(3) LED current sink matching in the high-voltage current sinks (HVLED1 through HVLED3) is given as the maximum matching value
between any two current sinks, where the matching between any two high voltage current sinks (X and Y) is given as (I_HVLEDX ( or
I_HVLEDY) × I_AVE(X-Y))/(I_AVE(X-Y)) × 100. In this test all three HVLED current sinks are assigned to Bank A.
6
Submit Documentation Feedback
Product Folder Links: LM3697
Copyright © 2013–2015, Texas Instruments Incorporated