XRP6840 Datasheet, PDF (3/17 Pages) Exar Corporation – 4.3A Supercapacitor Flash LED Driver with I2C

XRP6840
4.3A Supercapacitor Flash LED Driver with I²C
Parameter
Channel to Channel Current
Matching
Switching Frequency
Equivalent Resistance, 1X Mode
Equivalent Resistance, 1.5X
Mode
Min.
-3
2.0
LEDx Pin Dropout Voltage
Typ.
2.4
0.5
4
Max.
3
2.8
7
0.36
LEDx Pin Dropout Voltage
LED Short Detect Threshold
0.1
Thermal Regulation
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
0.1
0.2
0.4
0.01
150
10
Output Voltage Regulation (OVR) 5.2
5.3
5.4
Output Voltage Regulation
Hysteresis
RDY Pin Output Trip Threshold
RDY Pin Sink Current
SDA, SCL, RESET_N, FLASH
Input Logic Low Voltage
SDA, SCL, RESET_N, FLASH
Input Logic High Voltage
Turn-Off Time (T_OFF) Into
Shutdown
Flash Time Duration Before
Standby
50
V_O – 0.1
1
0.4
1.6
0.09
0.18
0.43
0.9
0.11
0.22
0.53
1.1
0.13
0.26
0.63
1.3
Units
%
MHz
Ω
Ω
V
V
V
%/^oC
o_C
o_C
V
mV
V
mA
V
Conditions
• 0mA < I_LED < 1.6A Per Channel, Note 3
•
• VIN = 3.7V, IOUT = 200mA
V_IN = 3.2V, V_OUT < V_{OUT_LIMIT},
• I_OUT = 200mA, Equivalent resistance =
[(V_IN x 1.5) - V_OUT] / I_OUT
Flash mode, V_IN = 3.4V, I_LED = 1A,
• Measure LED current at 95% I_LEDX-NOMINAL
at V_LEDX=0.8V
Torch mode, V_IN = 3.4V, I_LED = 80mA,
• Measure LED current at 95% I_LEDX-NOMINAL
at V_LEDX=0.8V
• VOUT – VLED, LED = 0mA for all DAC code
Driver turn OFF
Driver turn ON
Flash Mode, I_LED = 0mA, V_OUT Rising
STATUS2 Register: [B7 B6 B5] = 101
• OVR value is set by STATUS2 register
between 4.55V – 5.6V, all setting have
+/- 100mV tolerance
Flash Mode, I_LED = 0mA
STATUS2 Register: [B7 B6 B5] = 101
100mV below actual OVR value.
•
•
V
•
50
µs
RDY goes low when RESET_N goes from
high top low
s
• STATUS1 register [B1 B0]=00
s
• STATUS1 register [B1 B0]=01
s
• STATUS1 register [B1 B0]=10
s
• STATUS1 register [B1 B0]=11
I²C SPECIFICATIONS
I²C ADDRESSING FORMAT
S
XRP6840
Address
R/W
A
7-bit
1/0
Status
Data
8-bit
LED1 Data
LED2 Data
LED3 Data
A
A
A
A SP
8-bit
8-bit
8-bit
Start Condition
Acknowledgement
sent by the slave
© 2009 Exar Corporation
Acknowledgement
- sent by the slave when R/_W =0
- sent by master when R/_W =1
Fig. 2: I²C Data Input Format
3/17
Stop Condition
Rev. 1.0.0