SC621
5
Electrical Characteristics (continued)
Parameter Symbol Conditions Min Typ Max Units
LDO Electrical Speci cations (continued)
Load Regulation ΔV
LOAD
V
LDO1
= 3.3V, V
IN
= 3.7V,
I
LDO1
= 1mA to 100 mA
25
mV
V
LDO2
= 1.8V, V
IN
= 3.7V,
I
LDO2
= 1mA to 100 mA
20
Dropout Voltage
(5)
V
D
I
LDO1
= 100mA 100 150 mV
Current Limit I
LIM
200 mA
Power Supply
Rejection Ratio
PSRR
LDO1
2.5V < V
LDO1
< 3V, f < 1kHz, C
BYP
= 22nF, I
LDO1
= 50mA,
V
IN
= 3.7V with 0.5V
P-P
ripple
50
dB
PSRR
LDO2
f < 1kHz, C
BYP
= 22nF, I
LDO2
= 50mA,
V
IN
= 3.7V with 0.5V
P-P
ripple
60
Output Voltage Noise
e
n-LDO1
LDO1, 10Hz < f < 100kHz, C
BYP
= 22nF, C
LDO
= 1μF,
I
LDO1
= 50 mA, V
IN
= 3.7V, 2.5V < V
LDO1
< 3V
100
μV
RMS
e
n-LDO2
LDO2, 10Hz < f < 100kHz, C
BYP
= 22nF, C
LDO
= 1μF,
I
LDO2
= 50 mA, V
IN
= 3.7V
50
Minimum Output Capacitor C
LDO(MIN)
1μF
Digital I/O Electrical Speci cations (FLEN, SWIF)
Input High Threshold V
IH
V
IN
= 5.5V 1.6 V
Input Low Threshold V
IL
V
IN
= 3.0V 0.4 V
Input High Current I
IH
V
IN
= 5.5V -1 +1 μA
Input Low Current I
IL
V
IN
= 5.5V -1 +1 μA
SemWire Bit Rate f
SWIF
10 75 kbit/s
SemWire Start-up Time
(6)
t
EN
1ms
SemWire Disable Time
(7)
t
DIS
10 ms
SemWire Data Latch Delay
(8)
D
DL
5 bit
Notes:
(1) ΔV
F
is the voltage difference between any two LEDs.
(2) Once tripped, ash output will remain disabled until FLEN pin is cycled or reset via serial interface.
(3) Current matching equals ± [I
BL(MAX)
- I
BL(MIN
] / [I
BL(MAX)
+ I
BL(MIN)
].
(4) Test voltage is V
OUT
= 4.0V — a relatively extreme LED voltage — to force a transition during test. Typically V
OUT
= 3.2V for white LEDs.
(5) Dropout is de ned as (V
IN
- V
LDO1
) when V
LDO1
drops 100mV from nominal. Dropout does not apply to LDO2 since it has a maximum output voltage
of 1.8V.
(6) The SemWire start-up time is the minimum period that the SWIF pin must be held high to enable the part before commencing
communication.
(7) The SemWire disable time is the minimum period that the SWIF pin must be pulled low to shut the part down.
(8) The SemWire data latch delay is the maximum duration after communication has ended before the register is updated.
