MAX16821BEVKIT+ Maxim Integrated Products, MAX16821BEVKIT+ Datasheet - Page 14

• Manufacturer Part Number: MAX16821BEVKIT+
• Description: KIT EVAL FOR MAX16821B
• Manufacturer: Maxim Integrated Products

Specifications of MAX16821BEVKIT+

• Current - Output / Channel: 660mA
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 28V
• Features: Dimmable
• Voltage - Input: 7 ~ 24V
• Utilized Ic / Part: MAX16821
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

High-Power Synchronous HBLED
Drivers with Rapid Current Pulsing
The circuit in Figure 6 shows a step-up/step-down reg-
ulator. It is similar to the boost converter in Figure 5 in
that the inductor is connected to the input and the
MOSFET is essentially connected to ground. However,
rather than going from the output to ground, the LEDs
Figure 6. Typical Application Circuit for an Input-Referred Buck-Boost LED Driver (7V to 28V Input)
14
Input-Referenced Buck-Boost LED Driver
V
LED
______________________________________________________________________________________
C10
R8
R9
C9
C11
R5
C8
R7
R6
18
17
19
15
16
20
21
CLP
OVI
DIFF
EAOUT
EAN
CSN
CSP
SGND
14
I.C.
22
SENSE- SENSE+
OUTV
13
R3
23
RT/SYNC
12
24
C3
MAX16821A
MAX16821B
MAX16821C
R4
SGND
V
EN
11
25
CC
V
C7
IN
MODE
10
26
IN
ON/OFF
C6
CLKOUT
V
27
span from the output to the input. This effectively
removes the boost-only restriction of the regulator in
Figure 5, allowing the voltage across the LED to be
greater or less than the input voltage. LED current-
sensing is not ground-referenced, so a high-side cur-
rent-sense amplifier is used to measure current.
9
CC
C5
SGND
V
PGND
28
8
DD
N.C.
N.C.
BST
LX
DL
DH
4
7
6
5
3
2
1
L1
Q1
7V TO 28V
V
D1
IN
C1
C2
R2
C2
RS+
RS-
V
CC
OUT
LED
STRING
1 TO 6
LEDS
V
LED