MAX1962EEP+ Maxim Integrated Products, MAX1962EEP+ Datasheet - Page 16

• Manufacturer Part Number: MAX1962EEP+
• Description: IC DC-DC CTRL STP DWN 20-QSOP
• Manufacturer: Maxim Integrated Products
• Type: Step-Down (Buck)r

Specifications of MAX1962EEP+

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.8 ~ 4.95 V
• Current - Output: 20A
• Frequency - Switching: 500kHz, 1MHz
• Voltage - Input: 2.35 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-QSOP
• Power - Output: 727mW, 9.1mW
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

where:
The goal is to place the two zeros below crossover and
the two poles above crossover so that crossover
occurs with a single-pole slope. The compensation pro-
cedure is as follows:
Select the crossover frequency such that:
Select R1 such that:
where g
Place the first zero before the double pole:
Place the third pole at half the switching frequency:
2.35V to 5.5V, 0.5% Accurate, 1MHz PWM
Step-Down Controllers with Voltage Margining
Figure 5. Type 3 Compensation Network
16
V
V
where f
L
C
______________________________________________________________________________________
O
IN(MAX)
RAMP
O
= Output inductance
mEA
= Output capacitance
MAX1960
S
= Oscillator ramp voltage = 0.85 x 10
= 2mS.
= switching frequency
= Maximum input voltage
C
f
COMP
0
C
1
< f
2
≥
DH
DL
FB
LX
≥
2
ZESR
π
2
π
R
×
1
×
>>
R4
and f
0 75
.
0 5
V
g
IN
.
mEA
2
1
C2
1
0
×
×
<1/5
L
f
f
LC
S
O
×
R3
R2
R1
×

R
f
S
R
1
1
C
0
C3
C1
V
6
OUT
/f
S
,
If C2 < 10pF, it can be omitted.
Place the second pole after the ESR zero:
If:
where g
increase R1 and recalculate C1, C2, and C3.
Place the second zero at the double-pole frequency:
Set the output voltage:
Figure 6. Transfer Function for Type 3 Compensation
GAIN (dB)
fp1
mEA
C
R
3
= 2mS
4
≤
=
2
R
fz1
π
R
V
3
2
OUT
≥
R
×
≤
2
2
V
2
f
FB
π
0
<
fz2
π
-
g
×
V
×
×
FB
mEA
1
R
f
L
LC
1
f
1
0
ZESR
fp2
×
×
1
,
×
×
R
V
C
3
C
IN
,
×
0
3
V
fp3
FB
C
×
-
3
R
=
V
2
RAMP
0 8
.
FREQUENCY
V