WCDMA Cellular Phone 600mA
Buck Regulators
Ordering Information (continued)
PART
SYNC
FREQ (MHz)
OUTPUT VOLTAGE
TEMP RANGE
PIN-PACKAGE
UCSP MARK
MAX1821EBC*
MAX1821EUB
MAX1821XEBC*
MAX1821XEUB
No Sync
No Sync
13
13
Programmable
Programmable
Programmable
Programmable
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
3 ✕ 4 UCSP
10 µMAX
3 ✕ 4 UCSP
10 µMAX
AAC
—
AAV
—
*UCSP reliability is integrally linked to the user’s assembly methods, circuit board material, and environment. Refer to the UCSP
Reliability Notice in the UCSP Reliability section for more information.
Typical Operating Circuits (continued)
INPUT
2.6V TO
5.5V
BATT
LX
SHDN PGND
FB
MAX1821
SYNC COMP
OUTPUT
1.25V TO 5.5V
REF
SKIP GND
TOP VIEW AFTER ASSEMBLED ON PC BOARD (BUMPS AT THE BOTTOM)
1
2
3
4
SKIP
A
A1
COMP
OUT (FB)
REF
A2
A3
A4
SYNC
GND
B
B1
B4
SHDN
BATT
C
C1
C2
LX
PGND
C3
C4
( ) ARE FOR MAX1821 ONLY.
UCSP
TOP VIEW
Pin Configurations
SKIP 1
COMP 2
OUT (FB) 3
REF 4
GND 5
( ) ARE FOR MAX1821 ONLY.
MAX1820
MAX1821
µMAX
10 SYNC
9 SHDN
8 BATT
7 LX
6 PGND
16 ______________________________________________________________________________________