Datasheet
ELECTRICAL CHARACTERISTICS – LED AND PWM DRIVERS
Current range, Vin = 3.3 V,
I
O(SM3)
+
V(SM3REF)
R
FB3
TPS65820
SLVS663B – MAY 2006 – REVISED APRIL 2008 ..............................................................................................................................................................
www.ti.com
ELECTRICAL CHARACTERISTICS – ADC (continued)
Over recommended operating conditions (typical values at T
J
= 25 ° C), V(ADC_REF) =2.535v if external reference voltage is
used,application circuit as in Figure 3 (unless otherwise noted).
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
INTERNAL REFERENCE POWER CONSUMPTION
PD
ACTIVE
Power dissipation Conversion active 2.3 mW
PD
ARMED
Power dissipation Not converting 0.43 mW
TRIGGER TIMING CHARACTERISTICS
t
DELAY(TRG)
Trigger delay time accuracy Time range, set via I
2
C register ADC_DELAY 0 750 uS
Relative to typical value set via I
2
C – 20% 20%
t
WAIT(TRG)
Trigger wait time accuracy Time range, set via I
2
C register ADC_WAIT 0 20.48 mS
Relative to typical value set via I
2
C – 20% 20%
Over recommended operating conditions (typical values at T
J
= 25 ° C), application circuit as in Figure 3 (unless otherwise
noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SM3 BOOST CONVERTER, WHITE LED CONSTANT CURRENT DRIVER
V
VIN(SM3)
Input Voltage range V(OUT) = 3.3 V 3 4.7 V
V
OVP3
Output overvoltage trip OVP detected at V(SM3) > V
OVP3
26.5 29 30 V
V
HYS(OVP3)
Output overvoltage hysteresis OVP not detected at V(SM3) < V
OVP3
– V
HYS(OVP3)
1.8 V
LED current below regulation point at
V
SM3REF
LED current sense threshold 244 252 260 mV
V(FB3) < V
SM3REF
0 25 mA
I
O(SM3)
LED current
Total accuracy, I
O(SM3)
= 10 mA – 10% 10%
D
SM3SW
= 0% to 99.6%, set
D
SM3SW
LED switch duty cycle Duty cycle range via I
2
C, 256 steps 0.4%
minimum step
SM3_LF_OSC = 0 122
LED switch duty cycle pattern 256 pulses within repetition
F
REP_SM3
Hz
repetition rate rate time
SM3_LF_OSC = 1 183
R
DSON(SM3SW
LED switch MOSFET
V(OUT) = 3.6 V; I(SM3SW) = 20 mA 1 2 Ω
)
on-resistance
I
LKG(SM3SW)
LED switch MOSFET leakage 1 µ A
Power stage MOSFET
R
DSON(L3)
V(OUT) = 3.6 V; I(L3) = 200 mA 300 600 m Ω
on-resistance
I
LKG(L3)
Power stage MOSFET leakage 1 µ A
Power stage MOSFET current
I
MAX(L3)
3 V < V(OUT) < 4.7 V 400 500 600 mA
limit
PWM DRIVER, PWM OPEN DRAIN OUTPUT
V
OL(PWM)
Low level output voltage I(PWM)= 150 mA 0.5 V
Set via I
2
C, F
PWM
=
Frequency range Hz
0.5/1/1.5/2/3/4.5/7.8/15.6
F
PWM
PWM driver frequency
Total accuracy, relative to selected value -20% 20%
D
PWM
= 6.25% to 100%,
D
PWM
PWM driver duty cycle Duty cycle range set via I
2
C,
6.25% minimum step
LED_PWM DRIVER, LED_PWM OPEN DRAIN OUTPUT
D
LEDPWM
= 0% to 99.6%,
D
LEDPWM
LED_PWM driver duty cycle Duty cycle range set via I
2
C, 256 steps
0.4% minimum step
SM3_LF_OSC = 0 122
LED_PWM driver duty cycle 256 pulses within repetition
F
REP(LEDPWM)
Hz
pattern repetition rate rate time
SM3_LF_OSC = 1 180
16 Submit Documentation Feedback Copyright © 2006 – 2008, Texas Instruments Incorporated
Product Folder Link(s): TPS65820