MAX5098AATJ+T Maxim Integrated Products, MAX5098AATJ+T Datasheet - Page 23

• Manufacturer Part Number: MAX5098AATJ+T
• Description: IC CONV BUCK/BOOST DL 32TQFN-EP
• Manufacturer: Maxim Integrated Products
• Type: Step-Down (Buck), Step-Up (Boost)r

Specifications of MAX5098AATJ+T

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 2
• Voltage - Output: 0.8 ~ 0.85 V, 4.5 ~ 28 V
• Current - Output: 1A, 2A
• Frequency - Switching: 200kHz ~ 2.2MHz
• Voltage - Input: 4.5 ~ 19 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 32-TQFN Exposed Pad
• Power - Output: 2.76W
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3) Place a zero
where
and R
4) Calculate C
5) Place a pole
or 5 x f
is lower,
6) Place a second zero, f
whichever is lower.
7) Place a second pole at 1/2 the switching frequency.
Figure 5. Type III Compensation Network
F
C
≥ 10kΩ.
, whichever
C
C
C
R
I
CF
I
I
=
Converter with 80V Load-Dump Protection
I
for a target unity crossover frequency, f
2π
=
C
f
R1
R2
Z
R
(
Dual, 2.2MHz, Automotive Buck or Boost
F
1
×
2
V
______________________________________________________________________________________
1
OUT
=
=
R
π
f
=
C
I
×
2
2
×
2
=
f
P
π
π
0 5
π
L
1
V
.
2
×
×
REF
OUT
×
=
π
FB_
V
R
0 75
×
f
IN
Z
1
×
1
.
2
F
f
R
2
Z2
SW
π
f
F
P
×
1
-
+
C
×
×
C
×
g
×
1
1
CF
M
C
×
, at 0.2 x f
R
F
C
C
×
R
1
×
F
F
f
LC
OUT
I
I
C
R
C
×
at
−
I
F
F
R
C
×
×
I
I
0 75
R
×
C
at f
.
F
V
F
COMP_
OSC
)
ZERO ESR
×
−
C
1
f
LC
or at f
,
.
LC
C
.
,
The boost converter compensation gets complicated
due to the presence of a right-half-plane zero
f
phase while adding positive (+1) slope to the gain
curve. It is important to drop the gain significantly below
unity before the RHP frequency. Use the following pro-
cedure to calculate the compensation components:
1) Calculate the LC double-pole frequency, f
the right-half-plane-zero frequency.
where
Figure 6. Boost Application
ZERO,RHP
MAX5098A
BST_/VDD_
. The right-half-plane zero causes a drop in
SOURCE_
SOURCE_
DRAIN_
DRAIN_
PGND_
PGND_
SGND
VDRV
FB_
f
f
LC
V
ZERO RHP
L
R
=
(
MIN
2π
,
D
Boost Converter Compensation
×
=
)
=
1
=
L
−
I
(
OUT MAX
OUT
1
1
V
2
−
V
OUT
V
V+
−
π
IN
OUT
D R
D
(
×
)
×
2
L
C
OUT
(
OUT
MIN
)
)
C
OUT
LC
V
OUT_
, and
23