MAX16821AATI+ Maxim Integrated Products, MAX16821AATI+ Datasheet - Page 16

• Manufacturer Part Number: MAX16821AATI+
• Description: IC LED DRIVR HIGH BRIGHT 28-TQFN
• Manufacturer: Maxim Integrated Products
• Type: HBLED Driverr

Specifications of MAX16821AATI+

• Topology: High Side, Low Side, PWM, SEPIC, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: No
• Type - Primary: Automotive, Backlight
• Type - Secondary: High Brightness LED (HBLED)
• Frequency: 125kHz ~ 1.5MHz
• Voltage - Supply: 4.75 V ~ 5.5 V, 7 V ~ 28 V
• Voltage - Output: 5.1V
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 30A
• Internal Switch(s): Yes
• Low Level Output Current: 4000000 uA (Typ)
• High Level Output Current: 4000000 uA (Typ)
• Operating Supply Voltage: 7 V to 28 V
• Maximum Supply Current: 5.5 mA
• Maximum Power Dissipation: 2758 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Efficiency: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

In Figure 8, the input voltage goes from 7V to 28V and,
because of the ground-based current-sense resistor,
the output voltage can be as high as the input. The syn-
chronous MOSFET keeps the power dissipation to a
minimum, especially when the input voltage is large
compared to the voltage on the LED string. For the
High-Power Synchronous HBLED
Drivers with Rapid Current Pulsing
Figure 8. Application Circuit for a Low-Side Buck LED Driver
16
______________________________________________________________________________________
V
LED
C10
R9
R10
C9
C11
R6
C8
R9
R7
with Synchronous Rectification
17
18
19
15
16
20
21
CLP
OVI
DIFF
EAOUT
EAN
CSN
CSP
Low-Side Buck Driver
SGND
14
I.C.
22
SENSE- SENSE+
OUTV
13
R3
23
RT/SYNC
C3
12
24
MAX16821A
MAX16821B
MAX16821C
R4
SGND
V
EN
11
25
CC
V
C7
IN
ON/OFF
MODE
10
26
IN
C6
CLKOUT
inner average current-loop inductor, current is sensed
by resistor R1. To regulate the LED current, R2 creates
a voltage that the differential amplifier compares to
0.6V. Capacitor C1 is small and helps reduce the ripple
current in the LEDs. Omit C1 in cases where the LEDs
can tolerate a higher ripple current. The average current-
mode control scheme converts the input voltage to a
current source feeding the LED string.
V
27
9
CC
C5
SGND
V
PGND
28
8
DD
N.C.
N.C.
BST
LX
DL
DH
4
7
6
5
3
2
1
R5
D2
C4
Q1
Q2
7V TO 28V
V
L1
IN
R1
C1
C2
R2
V
LED
LED
STRING