ADP3290JCPZ-RL ON Semiconductor, ADP3290JCPZ-RL Datasheet - Page 25

• Manufacturer Part Number: ADP3290JCPZ-RL
• Description: IC CTLR BUCK SW REG 40-LFCSP
• Manufacturer: ON Semiconductor
• Type: Step-Down (Buck)r

Specifications of ADP3290JCPZ-RL

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 4
• Voltage - Output: 0.5 ~ 1.6 V
• Frequency - Switching: 250kHz ~ 4MHz
• Voltage - Input: 12V
• Operating Temperature: 0°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 40-LFCSP
• Output Voltage: 0.5 V to 1.6 V
• Output Current: 500 uA
• Input Voltage: - 0.3 V to + 6.3 V
• Supply Current: 25 mA
• Switching Frequency: 450 kHz
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

T
T
R’ is the PCB resistance from the bulk capacitors to the ceramics.
R
In this example, A
L
The compensation values can then be solved using:
account for layout and other parasitic effects (see the Tuning
the ADP3290 section). The final values selected after tuning
are:
response using these compensation values.
C
D
X
DS
C
These are the starting values prior to tuning the design that
Figure 12 and Figure 13 show the typical transient
+
+
A
is 250 pH for the 8 Al−Poly capacitors.
Figure 12. Typical Transient Response for Design
where:
C
R
C
C
is the total low−side MOSFET on resistance per phase.
+
V
C
A
A
B
FB
RT
X
= 120 pF
= 120 pF
= 28 kW
n
= 3.3 pF
R
V
E
C
C
R
R
R
C
VID
FB
X
O
O
L *
A
B
* R
+
R
+
+
D
B
C
A
T
Example Load Step
T
C
R
T
R
2 f
T
R
is 5, V
Z
A
D
1
C
A
B
B
D
A
E
+
+
) C
+
+
R
SW
R
DS
4
38.7 mW
3.04 ms
209 pF
1.21 kW
14.5 kW
2
O
448 ns
RT
673 ns
Z
+
equals 0.862 V, R’ is approximately 0.5 mW (assuming a 4−layer, 1 ounce motherboard), and
1 mW
R
0.862 V
O
+ 14.5 kW
+ 370 pF
+ 46.4 pF
+
1.21 kW
4.48 mF
2.45 ms
1.4 V
220 nH *
4.48 mF
209 pF
(eq. 43)
(eq. 44)
(eq. 45)
(eq. 46)
1 mW * 0.5 mW ) 396 mF
38.7 mW
http://onsemi.com
5 5.25 mW
2 450 kHz
396 mF
25
C
In continuous inductor current mode, the source current of
the high­side MOSFET is approximately a square wave with
a duty ratio equal to n × V
one­nth the maximum output current. To prevent large
voltage transients, a low ESR input capacitor, sized for the
maximum rms current, must be used. The maximum rms
capacitor current is given by:
often based on only 2000 hours of life. As a result, it
advisable to further derate the capacitor or to choose a
capacitor rated at a higher temperature than required.
Several capacitors can be placed in parallel to meet size or
height requirements in the design. In this example, the input
capacitor bank is formed by three 680 mF, 16 V aluminum
electrolytic capacitors and twelve 4.7 mF ceramic capacitors.
recommended maximum of 0.1 A/ms, an additional small
inductor (L > 370 nH at 18 A) should be inserted between the
converter and the supply bus. This inductor also acts as a
filter between the converter and the primary power source.
I
CRMS
IN
The capacitor manufacturer’s ripple−current ratings are
To reduce the input current di/dt to a level below the
Figure 13. Typical Transient Response for Design
Selection and Input Current di/dt Reduction
+ 3.04 ms
1 mW
+ 0.117
I
1-Vo, 3-COMP, 4-TRDET, D0~D2-PWM1~3
CRMS
2
+ D
1 mW
Example Load Release
115 A
I
+ 673 ns
O
OUT
N
4
/V
1
1
0.117
IN
D
* 1
and an amplitude of
* 1 + 14.3 A
(eq. 41)
(eq. 42)
(eq. 47)