MAX15046AAEE+T Maxim Integrated Products, MAX15046AAEE+T Datasheet - Page 13

no-image

MAX15046AAEE+T

Manufacturer Part Number
MAX15046AAEE+T
Description
DC/DC Switching Controllers 40V Synchronous Buck Controller
Manufacturer
Maxim Integrated Products
Datasheet

Specifications of MAX15046AAEE+T

Lead Free Status / Rohs Status
Lead free / RoHS Compliant
MAX15046 stops both DL and DH drivers and waits for
4096 switching cycles (hiccup timeout delay) before
attempting a new soft-start sequence. The hiccup-mode
protection remains active during the soft-start time.
The MAX15046 provides an internal undervoltage lock-
out (UVLO) circuit to monitor the voltage on V
UVLO circuit prevents the MAX15046 from operating
when V
4V, with 400mV hysteresis to prevent chattering on the
rising/falling edge of the supply voltage. DL and DH stay
low to inhibit switching when the device is in undervolt-
age lockout.
Thermal-overload protection limits total power dissipa-
tion in the MAX15046. When the junction temperature of
the device exceeds +150NC, an on-chip thermal sensor
shuts down the device, forcing DL and DH low, which
allows the device to cool. The thermal sensor turns the
device on again after the junction temperature cools by
20NC. The regulator shuts down and soft-start resets
during thermal shutdown. Power dissipation in the LDO
regulator and excessive driving losses at DH/DL trigger
thermal-overload protection. Carefully evaluate the total
power dissipation (see the Power Dissipation section) to
avoid unwanted triggering of the thermal-overload pro-
tection in normal operation.
The MAX15046 operates from 4.5V to 40V input supplies
and regulates output down to 0.6V. The minimum voltage
conversion ratio (V
controllable on-time. For proper fixed-frequency PWM
operation, the voltage conversion ratio must obey the
following condition:
where t
quency in Hertz. Pulse skipping occurs to decrease the
effective duty cycle when the desired voltage conversion
does not meet the above condition. Decrease the switch-
ing frequency or lower the input voltage V
pulse skipping.
CC
ON(MIN)
is lower than V
Applications Information
is 125ns and f
V
______________________________________________________________________________________
Effective Input-Voltage Range
V
OUT
Thermal-Overload Protection
OUT
IN
>
/V
t
IN
40V, High-Performance, Synchronous
ON(MIN)
UVLO
) is limited by the minimum
Undervoltage Lockout
. The UVLO threshold is
SW
×
is the switching fre-
f
SW
IN
to avoid
CC
. The
The maximum voltage conversion ratio is limited by the
maximum duty cycle (D
where V
in the inductor discharge path, including synchronous
rectifier, inductor, and PCB resistance. V
sum of the resistance in the charging path, including
high-side switch, inductor, and PCB resistance. In prac-
tice, provide adequate margin to the above conditions
for good load-transient response.
Set the MAX15046 output voltage by connecting a resis-
tive divider from the output to FB to GND (Figure 2).
Select R
with the following equation:
where V
table) and V
Resistor R
III compensation network. Review the values of R
R
Type III Compensation Network (Figure 4) section).
Figure 2. Adjustable Output Voltage
2
V
when using a Type III compensation network (see the
V
OUT
IN
DROP1
<
FB
2
D
1
from between 4kI and 16kI. Calculate R
max
= 0.59V (see the Electrical Characteristics
OUT
also plays a role in the design of the Type
is the sum of the parasitic voltage drops
-
D
can range from 0.6V to (0.85 O V
Buck Controller
MAX15046
max
R
1
=
Setting the Output Voltage
×
R
max
V
2
DROP2
FB
):
V
V
OUT
FB
+
V
(1-D
IN
-1
OUT
R
R
max
1
2
DROP2
) V
×
DROP1
IN
is the
1
).
and
13
1

Related parts for MAX15046AAEE+T