LTC3589HUJ#PBF Linear Technology, LTC3589HUJ#PBF Datasheet - Page 23

• Manufacturer Part Number: LTC3589HUJ#PBF
• Description: IC DC/DC CONV 8-OUTPUT 40QFN
• Manufacturer: Linear Technology

Specifications of LTC3589HUJ#PBF

• Applications: Handheld/Mobile Devices
• Current - Supply: 8µA
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: *
• Primary Input Voltage: 5.5V
• No. Of Outputs: 8
• Output Voltage: 5V
• Output Current: 1.6A
• No. Of Pins: 40
• Operating Temperature Range: -40°C To +150°C
• Msl: MSL 1 - Unlimited
• No. Of Ldo Regulators: 3
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

OPERATION
An inductor with low DC resistance will improve converter
effi ciency. Select an inductor with a DC current rating at least
1.5 times larger than the maximum load current to ensure
the inductor does not saturate during normal operations.
If short-circuit is a possible condition, the inductor should
be rated to handle the maximum peak current specifi ed
for the step-down converter. Table 8 shows inductors that
work well with the step-down switching regulators.
Input/Output Capacitor Selection
Low ESR (equivalent series resistance) ceramic capacitors
should be used at both the output and input supply of the
switching regulators. Only X5R or X7R ceramic capacitors
should be used because they retain their capacitance over
wider voltage and temperature ranges than other ceramic
types. A 22μF capacitor is suffi cient for the step-down
switching regulator outputs. For good transient response
and stability the output capacitor should retain at least
10μF of capacitance over operating temperature and bias
voltage. Place at least 4.7μF decoupling capacitance as
close as possible to each PV
recommended ceramic capacitor manufacturers.
Table 8. Inductors for Step-Down Switching Regulator 1
MANUFACTURERS
Coilcraft
Cooper
Sumida
TDK
TOKO
Tokin
Wurth
IN
pin. Refer to Table 12 for
VLCF5020T-2R2N2R6-1
VLF5014ST-1R0N2R7
VLF5014st-2R2N2R3
CDRH5D16NP-3R3N
XPL4020-222ML
LPS6225-222ML
LPS6225-332ML
LPS6225-472ML
XPL4020-102ML
XPL4020-152ML
H-DI-0630-2R4
H-DI-0630-3R8
H-DI-0520-2R2
PART NUMBER
1124BS-1R2N
1124BS-1R8N
SD25-2R2-R
7440530047
7440430022
SD14-1R2-R
SD14-1R5-R
SD14-2R0-R
744042001
744052002
744053003
VALUE
(μH)
2.2
2.2
3.3
2.0
2.2
3.3
2.2
2.2
2.2
2.4
3.8
2.5
3.0
2.2
1.0
1.5
4.7
1.2
1.5
1.0
1.2
1.8
1.0
4.7
BUCK-BOOST SWITCHING REGULATOR
Output Voltage Programming
Set the output voltage of the LTC3589/LTC3589-1 buck-
boost switching regulator using an external resistor divider
connected from BB_OUT to the feedback pin BB_FB and
to GND, as shown in Figure 4.
The value of R1 plays a role in setting the dynamics of the
buck-boost voltage mode control loop. In general, a larger
value for R1 will increase stability but reduce the speed of
the transient response. A good starting point is to choose
R1 equal to 1MΩ and calculate the value of R2 needed to set
the target output voltage. If a large output capacitor is used,
the bandwidth of the converter is reduced and R1 may be
reduced to improve transient response. If a large inductor
or small output capacitor is used then a larger R1 should
be used to bring the loop toward more stable operation.
DCR (Ω)
0.029
0.036
0.060
0.045
0.055
0.065
0.034
0.039
0.045
0.031
0.045
0.050
0.073
0.047
0.056
0.048
0.028
0.040
0.028
0.030
0.024
0.030
0.023
0.071
V
BB_OUT
CURRENT (A)
MAX DC
= 0.8 • 1+
4.00
3.60
2.60
3.90
3.50
3.00
3.35
2.56
2.80
2.60
2.60
2.91
2.7
2.3
2.6
2.9
2.7
2.6
2.5
2.4
2.8
2.4
2.5
2
LTC3589/LTC3589-1
SIZE (mm) W × L × H
R2
R1
5.2 × 5.2 × 1.45
5.2 × 5.2 × 1.45
5.2 × 5.2 × 1.45
4.2 × 4.2 × 2.0
4.2 × 4.2 × 2.0
4.2 × 4.2 × 2.0
6.0 × 6.0 × 2.0
6.0 × 6.0 × 2.0
6.0 × 6.0 × 2.0
5.2 × 5.2 × 2.5
5.0 × 5.0 × 2.0
5.3 × 5.3 × 2.0
6.3 × 6.3 × 3.0
6.3 × 6.3 × 3.0
5.8 × 5.8 × 2.8
5.8 × 5.8 × 2.8
4.8 × 4.8 × 2.8
5.6 × 5.6 × 1.8
4.8 × 4.6 × 1.4
4.8 × 4.6 × 1.4
4.5 × 4.7 × 1.8
4.5 × 4.7 × 1.8
4.8 × 4.8 × 1.8
5.8 × 5.8 × 1.8
(V)
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