MAX8645X/MAX8645Y
1x/1.5x/2x White LED Charge Pump with
Two LDOs in 4mm x 4mm TQFN
______________________________________________________________________________________ 13
PCB Layout and Routing
The MAX8645X/MAX8645Y are high-frequency,
switched-capacitor voltage regulators. For best circuit
performance, use a solid ground plane and place C
IN
,
C
OUT
, C3, and C4 as close as possible to the IC. There
should be no vias on C
IN
. Connect GND and PGND to
the exposed paddle directly under the IC. Refer to the
MAX8645Y evaluation kit for an example.
DESIGNATION VALUE MANUFACTURER PART DESCRIPTION
C1, C5 10µF TDK C2012X5R0J106M 10µF ±20%, 6.3V X5R ceramic capacitors (0805)
C3, C4, C6, C7 1µF TDK C1005X5R0J105M 1µF ±20%, 6.3V X5R ceramic capacitors (0402)
C8 0.01µF TDK C1005X7R1E103K 0.01µF ±10%, 25V X7R ceramic capacitor (0402)
D1–D4 — Nichia NSCW215T White LEDs
D5 (D5–D8) — Nichia NBCW011T White LEDs, 4 LEDs in one package
Panasonic
R
SETM
, R
SETF
As
required
Vishay
— 1% resistors
Table 3. Recommended Components for Figure 2
Chip Information
PROCESS: BiCMOS
9
8
11
12
13
14
10
23
22
25
26
27
28
24
21 20 19 18 17 16 15
123456 7
MAX8645X
MAX8645Y
THIN QFN
(4mm x 4mm, 0.4mm LEAD PITCH)
TOP VIEW
PGND
C1P
ENF
ENM2
P2
M1
M2
M3
M4
M5
M6
F1
F2
SETM
REFBP
LDO2
LDO1
GND
IN
PIN
ENM1
ENLDO
C2P
C1N
C2N
+ DENOTES A LEAD-FREE PACKAGE.
OUT
P1
SETF
Pin Configuration
Package Information
For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages
.
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
28 TDFN-EP T2844-1
21-0139
