MAX77231 Datasheet, PDF (1/10 Pages) Maxim Integrated Products – Ultra-Small Solution Size (< 7mm2)

MAX77231
EVALUATION KIT AVAILABLE
2.75V to 4.8V Input, 10mA Output, 35µV_RMS
Ultra-Low Noise Boost Regulator
General Description
The MAX77231 is optimized for boost applications, requiring
very low ripple/noise and small PCB space. Output ripple
and noise are suppressed to 35µV_RMS (in 1MHz BW) by
a PMOS linear post-regulator set 0.5V below the boost
regulator output to reject noise while optimizing efficiency.
The boost regulator operates using a 1µH/400mA inductor
and 2.2µF (0.22 (min) after derating) output capacitance. Fast
transient response and stable operation are guaranteed using
a current-limited PFM architecture.
A PMOS low-noise linear post-regulator attenuates boost
converter ripple by ~50dB (10MHz BW) before delivering
11.2V to the load. Other output voltages up to 16.2V can
be factory set. The LDO also disconnects the load from
the boost during shutdown, allowing the output to fall to
0V (true shutdown). Active discharge can also be activated.
The MAX77231 is packaged in a 9-bump wafer-level
package (WLP), providing a compact layout when combined
with the inductor and external capacitors. Total solution
size is less than 7mm².
Benefits and Features
●● Ultra-Small Solution Size (< 7mm²)
●● 35µV_RMS (typ) Output Ripple/Noise
●● 11.2V/10mA Output
●● Output Factory Trimmable from 11.2V to 16.2V
●● 125µA No Load Supply Current Output on < 1µA
Shutdown Supply Current
●● True Shutdown Load Disconnect
●● Selectable Active Discharge
●● 9-Bump, 1.238mm x 1.238mm x 0.35mm WLP
Applications
●● Low-Noise Bias Supply
●● Sensor Bias Supply
Ordering Information appears at end of data sheet.
Typical Operating Circuit
ON
OFF
INPUT
2.7 TO
4.8V
C1
2.2uF
6.3V
ENM
OUT
ENS ^MAX77231
IN
BSTP
L1 1µH
BST
400mA
LX
PGND
GND
C3
2.2µF 25V
OUTPUT
11.2V
10mA
C2
2.2µF
25V
19-6658; Rev 2; 5/16