350mA (max) Output Current ........................-40°C to +125°C
500mA (max) Output Current ........................-40°C to +105°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, see
www.maximintegrated.com/thermal-tutorial.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Electrical Characteristics
(V
IN
= +24V, V
DIM
= V
IN
, T
A
= T
J
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Input-Voltage Range
Ground Current
Supply Current
UNDERVOLTAGE LOCKOUT (UVLO)
V
CS
= V
IN
- 100mV, V
IN
rising from 4V
until V
LX
< 0.5V
IN
V
CS
= V
IN
- 100mV, V
IN
falling from 6.5V
until V
LX
> 0.5V
IN
Undervoltage-Lockout Hysteresis
SENSE COMPARATOR
MAX16822A, V
IN
- V
CS
rising from 140mV
until V
LX
> 0.5V
IN
MAX16822B, V
IN
- V
CS
rising from 140mV
until V
LX
> 0.5V
IN
MAX16822A, V
IN
- V
CS
falling from
260mV until V
LX
< 0.5V
IN
MAX16822B, V
IN
- V
CS
falling from
260mV until V
LX
< 0.5V
IN
Falling edge of V
IN
- V
CS
from 140mV to
260mV to V
LX
> 0.5V
IN
Rising edge of V
CS
- V
IN
from 260mV to
140mV to V
LX
< 0.5V
IN
V
IN
- V
CS
= 200mV
201
218
185
166
210
230
190
170
50
50
3.5
216
mV
236
198
mV
180
ns
ns
μA
0.5
6.25
6.5
V
6
V
SYMBOL
V
IN
No switching
V
DIM
< 0.6V, V
IN
= 12V
CONDITIONS
MIN
6.5
1.5
350
TYP
MAX
65
UNITS
V
mA
μA
Undervoltage Lockout
UVLO
Sense Voltage Threshold High
V
SNSHI
Sense Voltage Threshold Low
V
SNSLO
Propagation Delay to Output High
Propagation Delay to Output Low
CS Input Current
t
DPDH
t
DPDL
I
CSIN
www.maximintegrated.com
Maxim Integrated | 2
MAX16822A/MAX16822B
2MHz, High-Brightness LED
Drivers with Integrated MOSFET
and High-Side Current Sense
Electrical Characteristics (continued)
(V
IN
= +24V, V
DIM
= V
IN
, T
A
= T
J
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
INTERNAL MOSFET
V
IN
= V
DIM
= 24V, V
CS
= 23.9V,
I
LX
= 350mA
V
IN
= V
DIM
= 6.0V, V
CS
= 5.9V,
I
LX
= 350mA
V
DIM
= 0V, V
LX
= 65V
V
IN
- V
CS
= 100mV
V
CS
- V
IN
= 100mV
V
DIM
rising edge to V
LX
< 0.5V
IN
V
DIM
= V
IN
V
DIM
= 0V
Temperature rising
-3
165
10
200
15
0
2.8
0.6
0.85
1
1.7
2
10
μA
V
V
ns
μA
μA
°C
°C
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Drain-to-Source Resistance
R
DSON
LX Leakage Current
DIM INPUT
DIM Input-Voltage High
DIM Input-Voltage Low
DIM Turn-On Time
DIM Input Leakage High
DIM Input Leakage Low
THERMAL SHUTDOWN
Thermal-Shutdown Threshold
Thermal-Shutdown Threshold
Hsysteresis
THERMAL FOLDBACK
Thermal-Foldback Enable
Threshold Voltage
Thermal-Foldback Slope
TEMP_I Output Bias Current
I
LX_LEAK
V
IH
V
IL
t
DIM_ON
V
TFB_ON
FB
SLOPE
I
TEMP_I
V
DIM
= 5V
V
DIM
= 5V
1.9
2.0
0.75
2.12
V
1/V
25
26.5
28
μA
Typical Operating Characteristics
(V
IN
= V
DIM
= 48V, C
VCC
= 1µF, R
SENSE
= 0.62Ω, L = 220µH (connected between IN and CS). Typical values are at T
A
= +25°C,
unless otherwise noted.)
EFFICIENCY
vs. V
IN
MAX16822A toc01
DUTY CYCLE
vs. V
IN
90
80
DUTY CYCLE (%)
70
60
50
40
30
20
10
1 LED
3 LEDs
7 LEDs 9 LEDs
5 LEDs
11 LEDs
13 LEDs
15 LEDs
MAX16822A toc02
FREQUENCY
vs. V
IN
90
80
FREQUENCY (kHz)
70
60
50
40
30
20
10
0
1 LED
3 LEDs
13 LEDs
11 LEDs
9 LEDs
7 LEDs
5 LEDs
15 LEDs
MAX16822A toc03
100
95
EFFICIENCY (%)
90
85
1 LED
7 LEDs 9 LEDs
5 LEDs
3 LEDs
11 LEDs13 LEDs 15 LEDs
100
100
80
75
70
5
15
25
35
V
IN
(V)
45
55
65
0
5
15
25
35
V
IN
(V)
45
55
65
5
15
25
35
V
IN
(V)
45
55
65
www.maximintegrated.com
Maxim Integrated | 3
MAX16822A/MAX16822B
2MHz, High-Brightness LED
Drivers with Integrated MOSFET
and High-Side Current Sense
Typical Operating Characteristics (continued)
(V
IN
= V
DIM
= 48V, C
VCC
= 1µF, R
SENSE
= 0.62Ω, L = 220µH (connected between IN and CS). Typical values are at T
A
= +25°C,
unless otherwise noted.)
NORMALIZED I
LED
vs. V
IN
MAX16822A toc04
QUIESCENT CURRENT
vs. V
IN
450
QUIESCENT CURRENT (μA)
400
350
300
250
200
150
100
50
V
DIM
= 0V
0 5 10 15 20 25 30 35 40 45 50 55 60 65
V
IN
(V)
MAX16822A toc05
PWM DIMMING
AT 200Hz DUTY CYCLE (10%)
MAX16822A toc06
1.10
500
1.05
NORMALIZED I
LED
5 LEDs 7 LEDs
9 LEDs11 LEDs13 LEDs
15 LEDs
3 LEDs
I
LED
200mA/div
0
V
DIM
5V/div
0
V
IN
= 48V
8 LEDs
1ms/div
1.00
1 LED
0.950
0.90
0 5 10 15 20 25 30 35 40 45 50 55 60 65
V
IN
(V)
0
PWM DIMMING
AT 200Hz DUTY CYCLE (90%)
MAX16822A toc07
PWM DIMMING
AT 20kHz DUTY CYCLE (90%)
MAX16822A toc08
I
LED
200mA/div
0
V
DIM
5V/div
0
V
IN
= 48V
8 LEDs
1ms/div
10μs/div
I
LED
200mA/div
0
V
DIM
5V/div
0
LED CURRENT
vs. V
TEMP_I
450
400
LED CURRENT (mA)
350
I
LED
(A)
300
250
200
150
100
50
0
0
0.4
0.8
1.2
1.6
2.0
2.4
2.8
V
TEMP_I
(V)
0
0.1
V
IN
= 48V
0.3
MAX16822A toc09
I
LED
vs. TEMPERATURE
MAX16822A toc10
500
0.5
0.4
0.2
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
www.maximintegrated.com
Maxim Integrated | 4
MAX16822A/MAX16822B
2MHz, High-Brightness LED
Drivers with Integrated MOSFET
and High-Side Current Sense
Typical Operating Characteristics (continued)
(V
IN
= V
DIM
= 48V, C
VCC
= 1µF, R
SENSE
= 0.62Ω, L = 220µH (connected between IN and CS). Typical values are at T
A
= +25°C,
unless otherwise noted.)
LX
RDSON
vs. TEMPERATURE
V
IN
= 65V
0.9
0.8
0.7
0.6
0.5
0.4
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
MAX16822A toc11
I
TEMP_I
vs. TEMPERATURE
29.5
29.0
28.5
I
TEMP_I
(μA)
MAX16822A toc12
1.0
30.0
LX
RDSON
(Ω)
V
IN
= 48V
V
IN
= 6.5V
28.0
27.5
27.0
26.5
26.0
25.5
25.0
V
IN
= 48V
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Pin Description
PIN
1
2
3
4
5, 6
7
8
NAME
CS
IN
GND
PGND
LX
DIM
TEMP_I
FUNCTION
Current-Sense Input. Connect a resistor between IN and CS to program the LED current.
Positive Supply Voltage Input. Bypass with a 1μF or higher value capacitor to GND.
Ground
Power Ground
Switching Node
Logic-Level Dimming Input. Drive DIM low to turn off the current regulator. Drive DIM high to
enable the current regulator.
Thermal Foldback Control and Linear Input. Bypass with a 0.01μF capacitor to GND if thermal
foldback or analog dimming is used. See the
Thermal Foldback
section for more details.
Detailed Description
The MAX16822A/MAX16822B are step-down, constant-
current, high-brightness LED (HB LED) drivers. These
devices operate from a +6.5V to +65V input-voltage
range. The maximum output current is 500mA, if the
part is used at temperatures up to +105°C, or 350mA, if
it is used up to +125°C. A high-side current-sense
resistor sets the output current and a dedicated PWM
dimming input enables pulsed LED dimming over a
wide range of brightness levels.
A high-side current-sensing scheme and an on-board
current-setting circuitry minimize the number of exter-
nal components while delivering LED current with ±3%
accuracy, using a 1% sense resistor. See Figure 1 for
1. Introduction
Electronic scales are gradually replacing traditional measuring tools like springs and balances in everyday life, such as electronic price computing scales and electronic weigh...[详细]
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