MAX15066EWE+T Maxim Integrated Products, MAX15066EWE+T Datasheet - Page 15

• Manufacturer Part Number: MAX15066EWE+T
• Description: DC/DC Switching Controllers 4A 12V 500kHz w/Integrated Switch
• Manufacturer: Maxim Integrated Products

Specifications of MAX15066EWE+T

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Figure 3. Peak Current-Mode Regulator Transfer Model
The peak current-mode controller’s modulator gain is
attenuated by the equivalent divider ratio of the load
resistance and the current-loop gain. G
where R
frequency, L is the output inductance, D is the duty cycle
(V
calculated from the following equation:
where:
R1
R2
G
OUT
V
*C
GAIN BANDWIDTH AND INCREASED PHASE MARGIN FOR SOME
LOW-DUTY CYCLE APPLICATIONS.
MOD
FEEDBACK
OUT
FF
DIVIDER
K
/V
IS OPTIONAL, DESIGNED TO EXTEND THE REGULATOR’S
S
IN)
( )
LOAD
= +
DC
*C
V
1
, and K
S
FF
FB
SLOPE
=
S
REF
= V
SLOPE
g
FB
S
MC
N
______________________________________________________________________________________
OUT
S
S
=
g
×
MV
N
Regulator with Internal Power Switches
V
is the slope compensation factor



= +
=
SLOPE
1
/I
t
1
OUT(MAX)
SW
+
(
V
ERROR AMPLIFIER
High-Efficiency, 4A, Step-Down DC-DC
R
R
f
IN
OUT
L g
SW
V
LOAD
×
SLOPE
R
−
=
OUT
10
=
×
V
AVEA(dB)/20
MC
V
L
OUT
g
(
SLOPE
V
MV
×
, f
IN
×


K
SW
)
f
−
1
SW
S
R
V
C
C
MOD
× −
COMP
C
×
is the switching
OUT
(
× ×
f
1 D
SW
V
L g
COMP
)
becomes:
)
−
MC
NOTE: THE G
INJECTED INTO THE OUTPUT LOAD, I
SUCH CAN BE USED TO SIMPLIFY/MODEL THE MODULATION/CONTROL/POWER STAGE
CIRCUITRY SHOWN WITHIN THE BOXED AREA.
0.5
C


COMPARATOR



PWM
MOD
STAGE SHOWN ABOVE MODELS THE AVERAGE CURRENT OF THE INDUCTOR, I
As previously mentioned, the power modulator’s domi-
nate pole is a function of the parallel effects of the load
resistance and the current-loop gain’s equivalent imped-
ance:
Knowing that the ESR is typically much smaller than the
parallel combination of the load and the current loop,
e.g.,:
f
COMPENSATION
PMOD
f
PMOD
g
MC
CONTROL
RAMP
LOGIC
V
COMP
POWER MODULATOR
=
ESR
2
≈
π ×
OUT
G
2
MOD
π ×
, e.g., I
<<
C
OUT
C




L
R
V
OUT
= I
IN
V
LOAD
×
OUT
OUT
I
Q
Q
L
HS
LS
1





ESR
.
×




L
R
+
+
LOAD






1
R
K
LOAD
S
1
DCR
× −
1
+
I
f
1
L
SW
(
1 D


+
K


S
K
×
)
× −
S
L
f
−
(
SW
× −
I
1 D
C
OUT
f
OUTPUT FILTER
0.5
ESR
(
SW
OUT
1 D
AND LOAD
×


×
)
L




L
)
−
L
,
−
−
0.5
1
0.5
V
OUT




R




LOAD




−
−
1
15
1




