Datasheet

9Maxim Integrated
MAX16909
36V, 220kHz to 1MHz Step-Down Converter
with Low Operating Current
Pin Configurations
Pin Descriptions
PIN
NAME FUNCTION
TSSOP TQFN
1 15 FSYNC
Synchronization Input. The device synchronizes to an external signal applied to FSYNC.
The external clock frequency must be 10% greater than the internal clock frequency for
proper operation. Connect FSYNC to GND if the internal clock is used.
2 16 FOSC
Resistor-Programmable Switching-Frequency Setting Control Input. Connect a resistor
from FOSC to GND to set the switching frequency.
3 1
PGOOD
Open-Drain, Active-Low Output. PGOOD asserts when V
OUT
is below the 92.5% regula-
tion point. PGOOD deasserts when V
OUT
is above the 95% regulation point.
4 2 OUT
Switch Regulator Output. OUT also provides power to the internal circuitry when the out-
put voltage of the converter is set between 3V and 5V during standby mode.
5 3 FB
Feedback Input. Connect an external resistive divider from OUT to FB and GND to set
the output voltage. Connect to BIAS to set the output voltage to 5V.
6 4 COMP
Error-Amplifier Output. Connect an RC network from COMP to GND for stable operation.
See the Compensation Network section for more details.
7 5 BIAS
Linear Regulator Output. BIAS powers up the internal circuitry. Bypass with a 1FF
capacitor to ground.
8 6 GND Ground
9 7 BST
High-Side Driver Supply. Connect a 0.1FF capacitor between LX and BST for proper
operation.
+
+
TSSOP
13
4
SUPSW
OUT
14
3
SUPSW
PGOOD
15
2
EN
FOSC
16
1
TOP VIEW
I.C.FSYNC
10
7
SUP
BIAS
11
6
LX
COMP
9
8
BST
GND
12
5
LX
FB
EP
EP
MAX16909
MAX16909
15
16
14
13
6
5
7
OUT
COMP
8
PGOOD
SUPSW LX SUPSW
12
I.C.
4
12 11 9
FSYNC
FOSC
SUP
BST
GND
BIAS
FB LX
3
10
EN
TQFN
(5mm × 5mm)
TOP VIEW