Rainbow Electronics MAX5093 - Manual (Page 9)

MAX5092/MAX5093
4V to 72V Input LDOs with Boost Preregulator
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Pin Description
PIN NAME FUNCTION
1 IN
Input Supply Voltage. Bypass IN to the power ground plane with a 47µF (low-ESR) aluminum electrolytic
capacitor in parallel with a 1µF ceramic capacitor placed as close to the IC as possible.
2 EN
Enable Input. Drive EN high to turn on the IC. Drive EN low to disable the IC. Connect EN directly to IN for
always-on operation.
3 SGND
Signal Ground. Connect SGND to the signal ground plane and the exposed paddle. Connect the power
ground and signal ground plane together at the negative terminal of the input capacitor(s).
4 HOLD
Output Hold. When HOLD is forced low, the regulator stores the on-state of the output, allowing the
regulator to remain enabled even if EN is pulled low. To shut down the regulator, release HOLD after EN is
pulled low. If HOLD is unused, either connect HOLD to OUT or leave unconnected. HOLD is internally
connected to OUT through a 4µA pullup current.
5 PGND_LDO
LDO Power Ground. Connect PGND_LDO to the power ground plane. Connect the PGND_LDO ground and
signal ground plane together.
6 SET
Feedback Input for the LDO. Connect SET directly to SGND to set the output voltage of the LDO to the
preset voltage of 3.3V (MAX5092A/MAX5093A) or 5V (MAX5092B/MAX5093B). Connect SET to the center
tap of a resistor-divider connected between the LDO output and SGND to set the output voltage. V
SET
regulates to 1.24V when using an adjustable output.
7 OUT_SENSE LDO Regulator Output Sense. Connect OUT_SENSE to OUT at the output capacitor near the load.
8 OUT
LDO Regulator Output. Bypass OUT to the power ground plane with a 10µF ceramic capacitor. V OUT
regulates to a preset voltage of 3.3V (MAX5092A/MAX5093A) or 5V (MAX5092B/MAX5093B), or is
adjustable from 1.5V to 9V (MAX5902_) or 1.5V to 10V (MAX5093_).
9 BSOUT
Boost Regulator Output Voltage. Bypass BSOUT to the PGND_BST ground plane with a 22µF (low-ESR)
aluminum electrolytic capacitor in parallel with a 1µF ceramic capacitor placed as close to the IC as
possible. Connect BSFB directly to SGND to regulate the BOOST output to a fixed voltage of 7V for V
IN
≤
7V. V BSOUT follows V IN for V IN > 7V. V BSOUT is programmable up to 11V (MAX5092_) or 12V (MAX5093_)
by connecting BSFB to the center tap of an external resistor-divider connected between the BOOST output
and PGND_BST.
10, 11 LX
Inductor Connection to the Drain of the Internal Power MOSFET. Connect LX to the switched side of the
inductor. Connect pins 10 and 11 together as close to the device as possible. For the MAX5093, also
connect LX to the anode of the external Schottky diode.
12 PGND_BST
Boost Regulator Power Ground. Connect PGND_BST to the power ground plane. Connect the PGND_BST
ground plane and the signal ground plane together at the negative terminal of the input capacitor(s).
13 BSFB
Feedback Input for the Boost Regulator. Connect BSFB directly to SGND to set the boost regulator output
voltage to 7V. Connect BSFB to the center tap of an external resistor-divider connected between BSOUT
and SGND to set the output voltage. V
BSFB regulates to 1.24V when using an adjustable output.
14 VL
Internal Regulator Output for IC Supply. Bypass VL to SGND with a 1µF/6.3V ceramic capacitor placed as
close to the IC as possible. V
VL regulates to 5.5V with V BSOUT
≥ 5.5V.
15 CT
RESET Timeout Programming Input. Connect a capacitor from CT to SGND to set the RESET timeout
period. See the CT Capacitor Selection section.
16 RESET
RESET Output. RESET is an open-drain output that goes high impedance when V
OUT exceeds 92% of the
output voltage threshold after a programmed time delay. RESET pulls low immediately once V OUT drops
below 90% of the regulated LDO output voltage.
— EP
Exposed Paddle. Connect to the signal ground plane (SGND). Connect to a large-signal ground plane for
increased thermal performance.