mp2359dt MPS, mp2359dt Datasheet - Page 3

• Manufacturer Part Number: mp2359dt
• Description: 1.2a, 24v, 1.4mhz Step-down Converter In A Tsot23-6
• Manufacturer: MPS

PIN FUNCTIONS
TYPICAL PERFORMANCE CHARACTERISTICS
V
MP2359 Rev. 1.2
5/26/2008
Pin #
IN
1
2
3
4
5
6
= 12V, V
Name Description
GND
BST
SW
EN
FB
IN
OUT
Bootstrap. A capacitor is connected between SW and BS pins to form a floating supply across
the power switch driver. This capacitor is needed to drive the power switch’s gate above the
supply voltage.
Ground. This pin is the voltage reference for the regulated output voltage. For this reason care
must be taken in its layout. This node should be placed outside of the D1 to C1 ground path to
prevent switching current spikes from inducing voltage noise into the part.
Feedback. An external resistor divider from the output to GND, tapped to the FB pin sets the
output voltage. To prevent current limit run away during a short circuit fault condition, the
frequency foldback comparator lowers the oscillator frequency when the FB voltage is below
250mV.
On/Off Control Input. Pull EN above 1.2V to turn the device on.
Supply Voltage. The MP2359 operates from a +4.5V to +24V unregulated input. C1 is needed
to prevent large voltage spikes from appearing at the input.
Switch Output.
= 3.3V, L = 4.7µH, C1 = 10µF, C2 = 22µF, T
0.820
0.818
0.816
0.814
0.812
0.810
0.808
0.806
0.804
0.802
0.800
100
90
80
70
60
50
40
30
20
10
0
0.01
-50 -25
Efficiency vs
Load Current
Feedback Voltage vs
Die Temperature
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
DIE TEMPERATURE (
LOAD CURRENT ( A)
0
MP2359 – 1.2A, 24V, 1.4MHz STEP-DOWN CONVERTER IN A TSOT23-6
V
0.1
IN
25
V
= 18V
IN
= 24V
50
75 100 125
V
1
OUT
© 2008 MPS. All Rights Reserved.
= 2.5V
O
C)
www.MonolithicPower.com
150
10
A
100
1.50
1.48
1.46
1.44
1.42
1.40
1.38
1.36
1.34
1.32
1.30
90
80
70
60
50
40
30
20
10
= +25ºC, unless otherwise noted.
0
0.01
-50 -25
Efficiency vs
Load Current
Switching Frequency vs
Die Temperature
V
IN
DIE TEMPERATURE (
= 12V
LOAD CURRENT (A)
0
0.1
V
25
IN
= 24V
50
75 100 125
1
V
OUT
O
= 5V
C)
150
10
3