MAX8742EAI Maxim Integrated, MAX8742EAI Datasheet - Page 10

• Manufacturer Part Number: MAX8742EAI
• Description: Current & Power Monitors & Regulators
• Manufacturer: Maxim Integrated

500kHz Multi-Output Power-Supply Controllers
with High Impedance in Shutdown
10
SSOP
15
16
17
18
19
20
21
22
23
24
25
26
27
28
______________________________________________________________________________________
—
PIN
6, 16, 25, 32
TQFN
13
14
15
17
18
19
20
21
22
23
24
26
27
28
RUN/ON3
NAME
PGND
SHDN
BST5
BST3
SEQ
DH5
DH3
N.C.
LX5
DL5
DL3
LX3
V+
V
L
Pin-Strap Input that Selects the SMPS Power-Up Sequence:
Gate-Drive Output for the 5V, High-Side N-Channel Switch. DH5 is a floating driver
output that swings from LX5 to BST5, riding on the LX5 switching-node voltage.
Switching-Node (Inductor) Connection. Can swing 2V below ground without hazard.
Boost Capacitor Connection for High-Side Gate Drive (0.1µF)
Gate-Drive Output for the Low-Side Synchronous-Rectifier MOSFET. Swings 0 to V
Power Ground
5V Internal Linear-Regulator Output. V
After the 5V SMPS output has reached 4.5V (typ), V
output voltage through CSL5 for bootstrapping. Bypass to GND with 4.7µF. V
supplies up to 25mA for external loads.
Battery Voltage Input, 4.2V to 30V. Bypass V+ to PGND close to the IC with a 0.22µF
capacitor. Connects to a linear regulator that powers V
Shutdown Control Input, Active Low. Logic threshold is set at approximately 1V. For
automatic startup, connect SHDN to V+ through a 220kΩ resistor and bypass SHDN to
GND with a 0.01µF capacitor.
Gate-Drive Output for the Low-Side Synchronous-Rectifier MOSFET. Swings 0 to V L .
Boost Capacitor Connection for High-Side Gate Drive (0.1µF)
Switching-Node (Inductor) Connection. Can swing 2V below ground without hazard.
Gate-Drive Output for the 3.3V, High-Side N-Channel Switch. DH3 is a floating driver
output that swings from LX3 to BST3, riding on the LX3 switching-node voltage.
ON/OFF Control Input. See the Power-Up Sequencing and ON/ OFF Controls section.
No Connection
SEQ = GND: 5V before 3.3V, RESET output determined by both outputs
SEQ = REF: Separate ON3/ON5 controls, RESET output determined by 3.3V
output
SEQ = V
L
: 3.3V before 5V, RESET output determined by both outputs
Pin Description (continued)
FUNCTION
L
is also the supply-voltage rail for the chip.
L
automatically switches to the
L
.
L
L
.