MAX1836ETT50+T Maxim Integrated Products, MAX1836ETT50+T Datasheet - Page 11

• Manufacturer Part Number: MAX1836ETT50+T
• Description: IC DC-DC CONV 5V 6-TDFN
• Manufacturer: Maxim Integrated Products
• Type: Step-Down (Buck)r

Specifications of MAX1836ETT50+T

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 4.8 ~ 5.2 V
• Current - Output: 125mA
• Voltage - Input: 4.5 ~ 24 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 6-TDFN Exposed Pad
• Power - Output: 1.95W
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Commonly, instability is caused by excessive noise on
the feedback signal or ground due to poor layout or
improper component selection. When seen, instability
typically manifests itself as “motorboating,” which is
characterized by grouped switching pulses with large
gaps and excessive low-frequency output ripple during
no-load or light-load conditions.
High switching frequencies and large peak currents
make PC board layout an important part of the design.
Poor layout may introduce switching noise into the
feedback path, resulting in jitter, instability, or degrad-
ed performance. High-power traces, bolded in the typi-
cal application circuits (Figures 1 and 2), should be as
short and wide as possible. Additionally, the current
loops formed by the power components (C
L1, and D1) should be as tight as possible to avoid
radiated noise. Connect the ground pins of these
power components at a common node in a star-ground
configuration. Separate the noisy traces, such as the
LX node, from the feedback network with grounded
copper. Furthermore, keep the extra copper on the
board, and integrate it into a pseudoground plane.
When using external feedback, place the resistors as
close to the feedback pin as possible to minimize noise
Table 1. Component Suppliers
INDUCTORS
Coilcraft
Coiltronics
Sumida USA
Toko
CAPACITORS
AVX
Kemet
Panasonic
Sanyo
Taiyo Yuden
DIODES
Central Semiconductor
International
Nihon
On Semiconductor
Zetex
SUPPLIER
PC Board Layout and Grounding
______________________________________________________________________________________
MAX1836/MAX1837 Stability
24V Internal Switch, 100% Duty Cycle,
847-639-6400
561-241-7876
847-956-0666
847-297-0070
803-946-0690
408-986-0424
847-468-5624
619-661-6835
408-573-4150
516-435-1110
310-322-3331
847-843-7500
602-303-5454
516-543-7100
PHONE
IN
, C
OUT
,
coupling. The MAX1837 evaluation kit shows the rec-
ommended layout.
The typical application circuits’ (Figures 1 and 2) com-
ponents were selected for 9V battery applications.
However, the MAX1836/MAX1837 input voltage range
allows supply voltages up to 24V. Figure 6 shows a
modified application circuit for high-voltage applica-
tions. When using higher input voltages, verify that the
input capacitor’s voltage rating exceeds V
that the inductor value exceeds the minimum induc-
tance recommended in the Inductor Selection section.
Figure 7 shows the MAX1836/MAX1837 in a floating
ground configuration. By connecting what would nor-
mally be the output to the supply-voltage ground, the
IC’s ground pin is forced to regulate to -5V
(MAX183_EUT50) or -3.3V (MAX183_EUT33). Avoid
exceeding the maximum ratings of 24V between IN and
GND, and 5.5V between OUT and GND. Other negative
voltages may be generated by placing a resistive
divider across the output capacitor and connecting the
tap to FB in the same manner as the normal step-down
configuration.
Step-Down Converters
847-639-1469
561-241-9339
847-956-0702
847-699-1194
803-626-3123
408-986-1442
847-468-5815
619-661-1055
408-573-4159
516-435-1824
310-322-3332
847-843-2798
602-994-6430
516-864-7630
FAX
High-Voltage Step-Down Converter
Applications Information
Inverter Configuration
www.coilcraft.com
www.coiltronics.com
www.sumida.com
www.tokoam.com
www.avxcorp.com
www.kemet.com
www.panasonic.com
www.secc.co.jp
www.t-yuden.com
www.centralsemi.com
www.irf.com
www.niec.co.jp
www.onsemi.com
www.zetex.com
WEBSITE
IN(MAX)
and
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