Typical operating characteristics – Rainbow Electronics MAX8848Z User Manual
Page 4
High-Performance Negative Charge Pump
for 7 White LEDs in 3mm x 3mm Thin QFN
MAX8848Y/MAX8848Z
4 ______________________________________________________________________________________
Typical Operating Characteristics
(V
IN
= 3.6V, V
EN_
= V
IN
, circuit of Figure 1, T
A
= +25°C, unless otherwise noted.)
INPUT VOLTAGE RIPPLE (PEAK-TO-PEAK)
vs. INPUT VOLTAGE
MAX8848Y toc09
INPUT VOLTAGE (V)
INPUT VOLTAGE RIPPLE (mV)
3.9
3.6
3.3
3.0
10
20
30
40
0
2.7
4.2
20.8mA/LED
MAX8848Y
6.4mA/LED
16.0mA/LED
1.6mA/LED
LEDS HAVE MISMATCHED V
F
V
IN
FALLING
INPUT CURRENT vs. Li+ BATTERY
VOLTAGE (7 MISMATCHED LEDs)
MAX8848Y toc08
Li+ BATTERY VOLTAGE (V, TIME WEIGHTED)
SUPPLY CURRENT (mA)
3.4
3.5
3.6
3.7
3.8
3.9
50
100
150
200
250
0
4.2
3.0
20.8mA/LED
6.4mA/LED
16.0mA/LED
1.6mA/LED
SUPPLY CURRENT vs. SUPPLY VOLTAGE
(7 MISMATCHED LEDs)
MAX8848Y toc07
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
3.9
3.6
3.3
3.0
50
100
150
200
20.8mA/LED
6.4mA/LED
16.0mA/LED
1.6mA/LED
V
IN
FALLING
250
0
2.7
4.2
SUPPLY CURRENT vs. Li+ BATTERY
VOLTAGE (7 MATCHED LEDs)
MAX8848Y toc06
Li+ BATTERY VOLTAGE (V, TIME WEIGHTED)
SUPPLY CURRENT (mA)
3.4
3.5
3.6
3.7
3.8
3.9
50
100
150
200
250
0
4.2
3.0
20.8mA/LED
6.4mA/LED
16.0mA/LED
1.6mA/LED
SUPPLY CURRENT vs. SUPPLY VOLTAGE
(7 MATCHED LEDs)
MAX8848Y toc05
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
3.9
3.6
3.3
3.0
50
100
150
200
20.8mA/LED
6.4mA/LED
16.0mA/LED
1.6mA/LED
250
0
2.7
4.2
V
IN
FALLING
EFFICIENCY vs. Li+ BATTERY VOLTAGE
(7 MISMATCHED LEDs)
MAX8848Y toc04
Li+ BATTERY VOLTAGE (V, TIME WEIGHTED)
EFFICIENCY
P
LED
/P
BATT
(%)
3.4
3.5
3.6
3.7
3.8
3.9
60
1.6mA/LED
70
80
90
100
50
4.2
3.0
6.4mA/LED
20.8mA/LED
16mA/LED
EFFICIENCY
P
LE
D
/P
BATT
(%)
EFFICIENCY vs. SUPPLY VOLTAGE
(7 MISMATCHED LEDs)
MAX8848Y toc03
SUPPLY VOLTAGE (V)
3.9
3.6
3.3
3.0
60
70
80
90
20.8mA/LED
6.4mA/LED
1.6mA/LED
16.0mA/LED
100
50
2.7
4.2
V
IN
FALLING
EFFICIENCY vs. Li+ BATTERY VOLTAGE
(7 MATCHED LEDs)
MAX8848Y toc02
Li+ BATTERY VOLTAGE (V, TIME WEIGHTED)
EFFICIENCY
P
LED
/P
BATT
(%)
3.4
3.5
3.6
3.7
3.8
3.9
60
1.6mA/LED
70
80
90
100
50
4.2
3.0
6.4mA/LED
20.8mA/LED
16mA/LED
EFFICIENCY vs. SUPPLY VOLTAGE
(7 MATCHED LEDs)
MAX8848Y toc01
SUPPLY VOLTAGE (V)
EFFICIENCY
P
LE
D
/P
BATT
(%)
3.9
3.6
3.3
3.0
60
70
80
90
20.8mA/LED
6.4mA/LED
V
IN
FALLING
16.0mA/LED
1.6mA/LED
100
50
2.7
4.2