LM25085MYX/NOPB National Semiconductor, LM25085MYX/NOPB Datasheet - Page 16
![IC BUCK ADJ 8MSOP](/photos/7/37/73780/pkg_muy08a_sml.jpg)
LM25085MYX/NOPB
Manufacturer Part Number
LM25085MYX/NOPB
Description
IC BUCK ADJ 8MSOP
Manufacturer
National Semiconductor
Series
PowerWise®r
Type
Step-Down (Buck), Invertingr
Datasheet
1.LM25085MYENOPB.pdf
(24 pages)
Specifications of LM25085MYX/NOPB
Design Resources
LM(2)5085 Quick Start Calculator
Internal Switch(s)
No
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1.25 ~ 42 V
Frequency - Switching
Up to 1MHz
Voltage - Input
4.5 ~ 42 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
8-MSOP Exposed Pad, 8-HMSOP, 8-eMSOP
Power - Output
250mW
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Current - Output
-
Other names
LM25085MYX
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LM25085MYX/NOPB
Manufacturer:
TI
Quantity:
4 300
www.national.com
C
vides not only noise filtering and stability for the VCC regula-
tor, but also provides the surge current for the PFET gate
drive. The typical recommended value for C
good quality, low ESR, ceramic capacitor is recommended.
C
VCC pins. If the selected PFET has a Total Gate Charge
specification of 100 nC or larger, or if the circuit is required to
operate at input voltages below 7 volts, a larger capacitor may
be required. The maximum recommended value for C
1 µF.
IC Power Dissipation: The maximum power dissipated in the
LM25085 package is calculated using Equation 12 at the
VCC
VCC
: The capacitor at the VCC pin (from VIN to VCC) pro-
must be located as close as possible to the VIN and
VCC
is 0.47 µF. A
FIGURE 4. Example Circuit
VCC
is
16
maximum input voltage. The Total Gate Charge for the
Si7465 PFET is specified to be 40 nC (max) in its data sheet.
Therefore the total power dissipation within the LM25085 is
calculated to be:
Using an MSOP-8EP package with a θ
a temperature rise of 26°C from junction to ambient.
Final Design Example Circuit
The final circuit is shown in Figure 4, and its performance is
presented in Figure 5 through Figure 8.
P
DISS
= 42V x ((40 nC x 300 kHz) + 1.3 mA) = 559 mW
JA
of 46°C/W produces
30079342