EVALED2000P STMicroelectronics, EVALED2000P Datasheet - Page 12

• Manufacturer Part Number: EVALED2000P
• Description: LED Lighting Development Tools LED2000 3A 850KHz 3.0V to 18V Eval BRD
• Manufacturer: STMicroelectronics

Specifications of EVALED2000P

• Product Category: LED Lighting Development Tools
• Rohs: yes
• Product: Evaluation Boards
• Operating Supply Voltage: 3 V to 18 V
• For Use With: LED2000

Application notes
6
6.1
6.2
12/40
Application notes
Closing the loop
Figure 5.
G
The accurate control to output transfer function for a buck peak current mode converter can
be written as:
Equation 1
where R
sense circuitry,
ESR of the output capacitor.
F
the error amplifier that introduces a double pole at one half of the switching frequency.
H
CO
(s) accounts for the sampling effect performed by the PWM comparator on the output of
G
CO
(s) control to output transfer function
s
0
represents the load resistance, R
=
comparator
Block diagram of the loop
R
------ -
R
0
Current sense
i
PWM control
PWM
p
--------------------------------------------------------------------------------------------------
1
the single pole introduced by the LC filter and
+
R
-------------------------- -
-
+
0
L
T
SW
V
CONTROL
Doc ID 023432 Rev 3
m
1
C
V
1 D
IN
switch
switch
–
HS
LS
–
i
0.5
the equivalent sensing resistor of the current
R
C
C
C
-------------------- -
compensation
1
1
amplifier
+
+
network
error
L
----- -
-----
s
s
z
p
F
LC filter
H
s
-
+
V
FB
REF
z
the zero given by the
C
OUT
G
V
A
CO
OUT
O
(s)
(s)
α
LED
R
LED2000
S