MAX15041 Datasheet, PDF (7/16 Pages) Maxim Integrated Products – Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM Step-Down DC-DC Regulator with Internal Switches

Low-Cost, 3A, 4.5V to 28V Input, 350kHz, PWM
Step-Down DC-DC Regulator with Internal Switches
Typical Operating Characteristics (continued)
(V_IN = 12V, V_OUT = 3.3V, C_VDD = 1µF, C_IN = 22µF, T_A = +25°C, circuit of Figure 3 (see Table 1 for values), unless otherwise specified.)
DEVICE POWER DISSIPATION
vs. LOAD CURRENT
3.0
V_IN = 12V
2.5
V_OUT = 3.3V
2.0
V_OUT = 2.5V
V_OUT = 1.8V
1.5
V_OUT = 1.2V
1.0
0.5
0
0 0.5 1.0 1.5 2.0 2.5 3.0
LOAD CURRENT (A)
DEVICE POWER DISSIPATION
vs. LOAD CURRENT
3.0
V_IN = 5V
2.5
V_OUT = 3.3V
2.0
V_OUT = 2.5V
V_OUT = 1.8V
1.5
V_OUT = 1.2V
1.0
0.5
0
0 0.5 1.0 1.5 2.0 2.5 3.0
LOAD CURRENT (A)
Pin Description
PIN
1
2
3
4
5
6
7
8
9
10, 11, 12
13, 14
15, 16
—
NAME
V_DD
PGOOD
EN
COMP
FB
SS
SGND
I.C.
BST
LX
PGND
IN
EP
FUNCTION
Internal LDO 5V Output. Supply input for the internal analog core. Bypass with a ceramic capacitor of at
least 1µF to SGND. See Figure 3.
Power-Good Open-Drain Output. PGOOD goes low if FB is below 545mV.
Enable Input. EN is a digital input that turns the regulator on and off. Drive EN high to turn on the regulator.
Connect to IN for always-on operations.
Voltage Error-Amplifier Output. Connect the necessary compensation network from COMP to SGND.
Feedback Input. Connect FB to the center tap of an external resistor-divider from the output to SGND to set
the output voltage from 0.606V to 90% of V_IN.
Soft-Start Input. Connect a capacitor from SS to SGND to set the soft-start time (see the Setting the Soft-
Start Time section).
Analog Ground. Connect to PGND plane at one point near the input bypass capacitor return terminal.
Internally Connected. Connect to SGND.
High-Side MOSFET Driver Supply. Bypass BST to LX with a 10nF capacitor. Connect an external diode
(see the Diode Selection section) from V_DD to BST.
Inductor Connection. Connect the LX pin to the switched side of the inductor. LX is high impedance when
the IC is in shutdown mode, thermal shutdown mode, or V_DD is below the UVLO threshold.
Power Ground. Connect to the SGND PCB copper plane at one point near the input bypass capacitor
return terminal.
Input Power Supply. Input supply range is from 4.5V to 28V. Bypass with a ceramic capacitor of at least
22µF to PGND.
Exposed Pad. Connect to SGND externally. Solder the exposed pad to a large contiguous copper plane to
maximize thermal performance.
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