Typical operating characteristics (continued), Pin description – Rainbow Electronics MAX15040 User Manual
Page 7
MAX15040
High-Efficiency, 4A, Step-Down Regulator with
Integrated Switches in 2mm x 2mm Package
_______________________________________________________________________________________
7
Typical Operating Characteristics (continued)
(V
IN
= V
DD
= 3.3V, output voltage = 1.8V, I
LOAD
= 4A, and T
A
= +25°C, circuit of Figure 1, unless otherwise noted.)
Pin Description
BUMP
NAME
FUNCTION
A1, A2
GND
Analog/Power Ground. Connect GND to the PCB ground plane at one point near the input bypass
capacitor return terminal as close as possible to the device.
A3, A4
IN
Power-Supply Input. Input supply range is from 2.4V to 3.6V. Bypass IN to GND with a 22µF ceramic
capacitor in parallel to a 0.1µ F ceramic capacitor as close as possible to the device.
B1, B2,
B3
LX
Inductor Connection. All LX bumps are internally connected together. Connect all LX bumps to the
switched side of the inductor. LX is high impedance when the device is in shutdown mode.
B4
V
DD
Supply Input. V
DD
powers the internal analog core. Connect V
DD
to IN with a 10Ω resistor. Connect a 1µF
ceramic capacitor from V
DD
to GND.
C1
BST
High-Side MOSFET Driver Supply. Bypass BST to LX with a 0.1µF capacitor.
C2, C3
I.C.
Internally Connected. Leave unconnected or connect to ground.
C4
EN
Enable Input. Connect EN to GND to disable the device. Connect EN to V
DD
to enable the device.
D1
PWRGD
Power-Good Output. PWRGD is an open-drain output that goes high impedance when V
FB
exceeds 92.5%
of V
REFIN/SS
and V
REFIN/SS
is above 0.54V. PWRGD is internally pulled low when V
FB
falls below 90% of
V
REFIN/SS
or V
REFIN/SS
is below 0.54V. PWRGD is internally pulled low when the device is in shutdown
mode, V
DD
is below the internal UVLO threshold, or the device is in thermal shutdown.
D2
FB
Feedback Input. Connect FB to the center tap of an external resistor-divider from the output to GND to set
the output voltage from 0.6V to 90% of V
IN
.
D3
COMP
Voltage-Error Amplifier Output. Connect the necessary compensation network from COMP to FB and the
converter output (see the Compensation Design section). COMP is internally pulled to GND when the
device is in shutdown mode.
D4
REFIN/SS
External Reference Input/Soft-Start Timing Capacitor Connection. Connect REFIN/SS to a system voltage to
force FB to regulate to REFIN/SS voltage. REFIN/SS is internally pulled to GND when the device is in
shutdown and thermal shutdown mode. If no external reference is applied, the internal 0.6V reference is
automatically selected. REFIN/SS is also used to perform soft-start. Connect a minimum of 1nF capacitor
from REFIN/SS to GND to set the startup time (see the Soft-Start and Reference Input (REFIN/SS) section).
STARTING INTO PREBIAS OUTPUT ABOVE
NOMINAL SETPOINT WITH NO LOAD
MAX15040 toc18
1ms/div
V
EN
V
OUT
2V/div
0
V
PWRGD
2V/div
0
1V/div
CASE TEMPERATURE
vs. AMBIENT TEMPERATURE
MAX15040 toc19
AMBIENT TEMPERATURE (
°C)
CASE TEMPERATURE (
°C)
60
35
-15
10
-20
0
20
40
80
60
100
120
-40
-40
85
CASE = TOP SIDE OF DEVICE
MEASURED ON A MAX15040EVKIT
I
OUT
= 4A