MAX16821AATI+ Maxim Integrated Products, MAX16821AATI+ Datasheet - Page 17

• 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 9, the input voltage goes from 7V to 28V, the LED
load is connected from the positive side to the current-
sense resistor (R1) in series with the inductor, and MODE
is connected to V
inductor, current is sensed by resistor R1 and is then
transferred to the low side by the high-side current-sense
Figure 9. Application Circuit for a High-Side Buck LED Driver
C10
C9
C11
R6
C8
R8
R7
with Synchronous Rectification
CC
______________________________________________________________________________________
17
18
19
15
16
20
21
. For the inner average current-loop
CLP
DIFF
OVI
EAOUT
EAN
CSN
CSP
SGND
14
I.C.
I.C.
22
High-Side Buck Driver
SENSE- SENSE+
OUTV
R3
13
23
Drivers with Rapid Current Pulsing
RT/SYNC
12
C3
24
High-Power Synchronous HBLED
MAX16821C
MAX16821A
MAX16821B
R4
SGND
V
EN
11
25
CC
V
C7
IN
MODE
10
26
IN
ON/OFF
C6
CLKOUT
V
27
9
CC
C5
SGND
V
PGND
28
8
DD
N.C.
N.C.
BST
LX
DL
DH
amplifier, U2. The voltage appearing across resistor R11
becomes the average inductor current-sense voltage for
the inner average current loop. To regulate the LED
current, R2 creates a voltage that the differential ampli-
fier compares to its internal reference. Capacitor C1 is
small and is added to reduce the ripple current in the
LEDs. In cases where the LEDs can tolerate a higher
ripple current, capacitor C1 can be omitted.
4
5
3
7
6
2
1
R5
D1
7V TO 28V
C4
V
IN
Q1
Q2
C2
L1
C1
R1
LED
STRING
RS+
RS-
V
U2
CC
OUT
R2
R11
17