LM26001QMXA/NOPB National Semiconductor, LM26001QMXA/NOPB Datasheet - Page 16
![IC REG SW 1.5A W/SLEEP 16-TSSOP](/photos/7/36/73657/pkg_mxa16a_sml.jpg)
LM26001QMXA/NOPB
Manufacturer Part Number
LM26001QMXA/NOPB
Description
IC REG SW 1.5A W/SLEEP 16-TSSOP
Manufacturer
National Semiconductor
Series
PowerWise®r
Type
Step-Down (Buck)r
Datasheet
1.LM26001QMXANOPB.pdf
(18 pages)
Specifications of LM26001QMXA/NOPB
Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1.25 ~ 35 V
Current - Output
1.5A
Frequency - Switching
150kHz ~ 500kHz
Voltage - Input
4 ~ 38 V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
16-TSSOP Exposed Pad, 16-eTSSOP, 16-HTSSOP
Power - Output
2.6W
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
*LM26001QMXA/NOPB
LM26001QMXA
LM26001QMXA
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LM26001QMXA/NOPB
Manufacturer:
TI/NSC
Quantity:
19 400
www.national.com
Thermal Considerations and TSD
Although the LM26001 has a built in current limit, at ambient
temperatures above 80°C, device temperature rise may limit
the actual maximum load current. Therefore, temperature rise
must be taken into consideration to determine the maximum
allowable load current.
Temperature rise is a function of the power dissipation within
the device. The following equations can be used to calculate
power dissipation (PD) and temperature rise, where total PD
is the sum of FET switching losses, FET DC losses, drive
losses, Iq, and VBIAS losses:
PD
Psw
TOTAL
DC
= D x Iload
= Psw
P
QG
P
VBIAS
AC
= Vin x 4.6 x 10
P
+ Psw
2
Iq
= Vbias x I
x (0.2 + 0.00065 x (T
= Vin x Iq
DC
+ PQG + P
VBIAS
-9
x fsw
Iq
+ P
j
- 25))
VBIAS
16
Given this total power dissipation, junction temperature can
be calculated as follows:
Where θ
with a large copper plane area. θ
metallization area.
To calculate the maximum allowable power dissipation, as-
sume Tj = 125°C. To ensure that junction temperature does
not exceed the maximum operating rating of 125°C, power
dissipation should be verified at the maximum expected op-
erating frequency, maximum ambient temperature, and min-
imum and maximum input voltage. The calculated maximum
load current is based on continuous operation and may be
exceeded during transient conditions.
If the power dissipation remains above the maximum allow-
able level, device temperature will continue to rise. When the
junction temperature exceeds its maximum, the LM26001 en-
gages Thermal Shut Down (TSD). In TSD, the part remains
in a shutdown state until the junction temperature falls to with-
in normal operating limits. At this point, the device restarts in
soft-start mode.
JA
=38°C/W (typically) when using a multi-layer board
Tj = Ta + (PD
TOTAL
JA
varies with board type and
x θ
JA
)