MAX15017BATX+T Maxim Integrated Products, MAX15017BATX+T Datasheet - Page 21

• Manufacturer Part Number: MAX15017BATX+T
• Description: IC DC/DC CONV 1A 36-TQFN-EP
• Manufacturer: Maxim Integrated Products
• Type: Step-Down (Buck)r

Specifications of MAX15017BATX+T

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 1.26 ~ 32 V
• Current - Output: 1A
• Frequency - Switching: 135kHz ~ 500kHz
• Voltage - Input: 7.5 ~ 40 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 36-TQFN Exposed Pad
• Power - Output: 2.1W
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The error amplifier gain between f
mately equal to R5 / (R6 || R3).
The ESR zero frequency f
higher than the double-pole frequency f
the value of R5 can be calculated as:
C7 can still be calculated as:
f
The MAX15014–MAX15017 LDO regulator features Dual
Mode™ operation: it can operate in either a preset voltage
mode or an adjustable mode. In preset voltage mode,
internal trimmed feedback resistors set the internal linear
regulator to 3.3V or 5V (see the Selector Guide ). Select
preset voltage mode by connecting SET_LDO to ground.
In adjustable mode, select an output voltage between
1.5V and 11V using two external resistors connected as a
voltage-divider to SET_LDO (see Figure 5). Set the output
voltage using the following equation:
where V
for R2 is around 50kΩ.
The RESET timeout period is adjustable to accommo-
date a variety of µP applications. Adjust the RESET
timeout period by connecting a capacitor (C
between CT and SGND.
where V
1.241V (typ), I
(typ), t
Dual Mode is a trademark of Maxim Integrated Products, Inc.
P3
is set at 5xf
RP
SET_LDO
CT-TH
is in seconds and C
1A, 4.5V to 40V Input Buck Converters with
R
Setting the RESET Timeout Delay
5
V
CT-THQ
C
= delay comparator threshold (rising) =
=
OUT
C
. Therefore, C8 is calculated as:
C
R
R
8
t
= 1.241V and the recommended value
RP
7
3
3
______________________________________________________________________________________
=
=
×
+
=
2
=
R
R
V
0 5 2
π
= CT charge current = 2 x 10
Regulator Output Voltage
SET LDO
6
6
C
.
×
CT
×
C
×
I
ZESR
Setting the LDO Linear
CT THQ
_
G
7
×
π
MOD DC
×
C
−
V
CT
1
×
R
7
C
R
5
might not be very much
⎛
⎜
⎝
T T
5
is in Farads.
1
×
_
f
−
C
+
P2
×
f
P
2
f
R
H
3
R
LC
and f
1
2
×
−
⎞
⎟
⎠
f
1
LC
50mA Auxiliary LDO Regulators
2
P3
LC
, therefore
is approxi-
CT
-6
A
)
Connect CT to LDO_OUT to select the internally fixed
timeout period. C
tor. Ceramic capacitors are recommended; do not use
capacitors lower than 200pF to avoid the influence of
parasitic capacitances.
For stable operation over the full temperature range and
with load currents up to 50mA, use a 10µF (min) output
capacitor (C
reduce noise and improve load-transient response, sta-
bility, and power-supply rejection, use larger output
capacitor values. Some ceramic dielectrics such as Z5U
and Y5V exhibit very large capacitance and ESR varia-
tion with temperature and are not recommended. With
X7R or X5R dielectrics, 15µF should be sufficient for
operation over their rated temperature range. For higher-
ESR tantalum capacitors (up to 1Ω), use 22µF or more to
maintain stability. To improve power-supply rejection
and transient response use a minimum 0.1µF capacitor
between IN_LDO and SGND.
The MAX15014–MAX15017 are available in a thermally
enhanced package and can dissipate up to 2.86W at
T
+160°C, the part shuts down and is allowed to cool.
After the die cools by 20°C, the device restarts with a
soft-start. The power dissipated in the device is the
sum of the power dissipated in the LDO, power dissi-
pated from supply current (P
switching the internal power MOSFET (P
Figure 5. Setting the Output Voltage Using a Resistive Divider
A
= +70°C. When the die temperature reaches
LDO_OUT
MAX15014–
CT
MAX15017
V
IN_LDO
SGND
IN_LDO
must be low-leakage-type capaci-
) with a maximum ESR of 0.4Ω. To
Capacitor Selection and
LDO_OUT
SET_LDO
Q
), transition losses due to
Regulator Stability
Power Dissipation
SW
R1
R2
), and the
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