LTC3589HUJ#PBF Linear Technology, LTC3589HUJ#PBF Datasheet - Page 27

• 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
Capacitor Selection
Low ESR ceramic capacitors should be used at both the
output and input supply of the buck-boost switching
regulator. 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 sufficient for the buck-boost switch-
ing regulator output. 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 PV
ceramic capacitor manufacturers.
Table 12. Ceramic Capacitor Manufacturers
AVX
Murata
Taiyo Yuden
Vishay Siliconix
TDK
SLEWING DAC REFERENCE OPERATION
Controlling the DAC References
The three LTC3589/LTC3589-1 step-down switching
regulators and linear regulator LDO2 have programmable
DAC reference inputs. Each DAC is programmable from
0.3625V to 0.75V in 12.5mV steps:
The DAC references may be commanded to independently
slew between two voltages at one of four selectable slew
rates. Table 13 summarizes the command registers used
to control slewing DAC operation.
V
OUT
= 1+
IN4
R2
R1
pin. Refer to Table 12 for recommended
• (0.3625 + BxDTVx • 0.0125)(V)
www.avxcorp.com
www.murata.com
www.t-yuden.com
www.vishay.com
www.tdk.com
Table 13. Slewing DAC Command Register Control Summary
COMMAND
REGISTER[BIT]
VCCR[0], VCCR[2],
VCCR[4], VCCR[6]
VCCR[1], VCCR[3],
VCCR[5], VCCR[7]
B1DTV1[4-0], B2DTV1[4-0],
B3DTV1[4-0], L2DTV1[4-0]
B1DTV1[5], B2DTV1[5],
B3DTV1[5], L2DTV1[5]
B1DTV2[4-0], B2DTV2[4-0],
B3DTV2[4-0], L2DTV2[4-0]
VRRCR[1-0], VRRCR[3-2],
VRRCR[5-4], VRRCR[7-6]
Setting and Slewing the DAC Outputs
The 5-bit word in dynamic target voltage command reg-
isters B1DTV1, B2DTV1, B3DTV1, and L2DTV1 programs
reference voltage V1. The 5-bit word in command regis-
ters B1DTV2, B2DTV2, B3DTV2, and L2DTV2 programs
reference voltage V2. A resistor divider network on the
output and feedback pins of the regulators set their
output voltage.
LTC3589/LTC3589-1
FUNCTION
Voltage Change Control Register
G0 / Slew
Write a 1 to Initiate a Slew to the Voltage
Selected in VCCR[1], VCCR[3], VCCR[5],
VCCR[7] Respectively.
Bits are Reset to 0 at the End of the Slew
Operation.
Voltage Change Control Register
Dynamic Target Select
Write a 0 to Select Voltage V1 Stored in
Registers B1DTV1[4-0], B2DTV1[4-0],
B3DTV1[4-0], L2DTV1[4-0].
Write a 1 to Select Voltage V2 in
Registers B1DTV2[4-0], B2DTV2[4-0],
B3DTV2[4-0], L2DTV2[4-0].
Dynamic Target Voltage 1
Five Bits Corresponding to V1 Output
from Each DAC.
PGOOD Mask
Write a 1 to Continue Normal PGOOD
Operation When Slewing.
Write a 0 to Force PGOOD to Pull Low
During Slew.
Dynamic Target Voltage 2
Five Bits Corresponding to V2 Output
from Each DAC.
Voltage Ramp Rate Control
Two Bits That Set the DAC Output Slew
Rate for Step-Down Switching Regulator
and LDO2.
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