LTC3423EMS#TR Linear Technology, LTC3423EMS#TR Datasheet - Page 10

• Manufacturer Part Number: LTC3423EMS#TR
• Description: IC SYNC BOOST CONV MCRPWR 10MSOP
• Manufacturer: Linear Technology
• Type: Step-Up (Boost)r

Specifications of LTC3423EMS#TR

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 1.5 ~ 5.5 V
• Current - Output: 1A
• Frequency - Switching: 3MHz
• Voltage - Input: 0.5 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Power - Output: 750mW
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: LTC3423EMSTR

APPLICATIO S I FOR ATIO
LTC3423/LTC3424
The output filter pole is given by:
where C
The output filter zero is given by:
where R
A troublesome feature of the boost regulator topology is
the right half plane zero (RHP) and is given by:
At heavy loads this gain increase with phase lag can occur
at a relatively low frequency. The loop gain is typically
rolled off before the RHP zero frequency.
TYPICAL APPLICATIO
10
G
G
f
f
f
FILTERZERO
FILTERPOLE
RHPZ
DC
CONTROL
= G
OUT
ESR
CONTROLOUTPUT
2
is the output filter capacitor.
is the capacitor equivalent series resistance.
• • •
V
IN
2 •
2
I
2 • •
OUT
L V
•
U
V
•
R
IN
V
O
OUT
O
, G
I
2
OUT
R
U
ESR
Hz
EA
• G
•
1
C
1 = Burst Mode OPERATION
EA
OUT
•
2000
C
0 = FIXED FREQ
OUT
Hz
U
V
W
IN
= 0.9V TO 1.5V
Hz
V
DD
* SET RB TO FORCE BETA OF 100; RB =
10
Typical Application with Output Disconnect
3
2
6
1
LTC3423/LTC3424
V
SHDN
MODE/SYNC
V
R
IN
DD
t
U
V
GND
SW
OUT
V
FB
C
4
7
8
9
5
The typical error amp compensation is shown in Figure 3.
The equations for the loop dynamics are as follows:
Refer to Application Note AN76 for more closed loop
examples.
(V
f
which is extremelyclose to DC
f
f
OUT
POLE
ZERO
POLE
– V
INMIN
I
1
2
OUTMAX
1
– 0.7V) • 100
2
2
2
• •
• •
• •
FMMT717
ERROR
ZETEX
AMP
20 10
R
R
1
RB*
1
+
–
Z
Z
3423/24 TA03
•
1
•
•
C
C
C5
1 F
1.25V
Figure 3
V
C
C
6
OUT
FB
V
8
9
1
2
C
•
Hz
Hz
C
C
1
R
Z
Hz
C
C1
C
C2
V
OUT
R1
R2
3423/24 F03
34234f