MC34704AEP Freescale Semiconductor, MC34704AEP Datasheet - Page 35

• Manufacturer Part Number: MC34704AEP
• Description: IC POWER MANAGEMENT 56-QFN
• Manufacturer: Freescale Semiconductor

Specifications of MC34704AEP

• Applications: Processor
• Current - Supply: 86mA
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 56-QFN
• Output Voltage: 5 V
• Input Voltage: 2.7 V to 5.5 V
• Switching Frequency: 750 KHz to 2 MHz
• Mounting Style: SMD/SMT
• Number Of Outputs: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

indicate a fault due to thermal limit, where x corresponds to
each regulator from REG1 to REG8, except REG7
Regulator Fault Register
indicate that a fault had occurred on each regulator. The
processor can just access this register periodically to
determine system status. This reduces the access cycles. If
a regulator fault register asserted, then the processor can
access that regulator’s registers to see what kind of fault had
occurred.
SPECIAL REGISTERS
REG3 Fine Voltage Scaling Register
that enables to lower the output voltage in 0.5% steps. The
34704 assigns an 8-bit register (REG3DAC) to the REG3
Digital to analog converter for the FB3 voltage generation.
Output votlage must be reduced gradually to avoid a OV/UV
fault to occur.
REGISTER DESCRIPTION SUMMARY TABLE
Analog Integrated Circuit Device Data
Freescale Semiconductor
The 34704 assigns 1 bit for each regulator (TSDFx) to
The 34704 assigns 1 bit for each regulator (FAULTx) to
Regulator 3 has an additional fine output voltage scaling
GENERAL1
GENERAL2
GENERAL3
REG2SET1
Register
VGSET1
VGSET2
ADDR
$01
$02
$03
$04
$05
$06
FAULT
TSDF
False
False
True
True
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R
OVUVSET1
OVUVSET2
DVSSTAT1
SDDELAY
DVSSET1
DVSSET2
Bit Name
CCDSEQ
ONOFFx
ALLOFF
SSTIME
COLDF
SHTD
-
bit
bit
0
1
0
1
Bits
1:0
3:2
3:0
1:0
4:1
5:1
4:1
4
3
4
0
0
0
GrpC/E power sequence selection
Hard shutdown delay timer selection
GrpA,C,D,E On/off bits
Soft shutdown bit (turn off all regulators)
Soft start configuration latch
Cold power up detection flag
Hard Shutdown detection flag
Set REG1/VG response type to OV/UV
REG1 DVS value setting
DVS voltage level status flag
REG1 fault flags: Thermal SD, SC, ILim, UV and OV
Set REG2 response type to OV/UV
REG2 DVS value setting
REG7 Independent ON/OFF Control (Only on 34704A)
REG7 when REG6 is not needed. Care must be taken when
turning on REG7 to avoid inrush currents during regulator
ramp-up. Following Process must be followed to assure
successful turn on of REG7.
1. Set EN0 and clear DISCHR_B on REG7CR0 register
2. After 1ms or more, set EN1 on REG7CR0 register
3. Set REG7DAC register to $00
4. Gradually shift up REG7DAC register from $00 to $D9
The 34704B provide two register to independently turn on
to ramp-up the output voltage in a soft-start like wave.
Soft start timing is dependant of I2C communication
speed and number of bit you change per writing, for
instance use 4,8 or 16 bits increase to ramp up the
output voltage.
55
...
1
2
3
4
5
6
REG7 independent start up example
Register Address
Description
$58
$58
$59
$59
$59
$59
$59
...
LOGIC COMMANDS AND REGISTERS
FUNCTIONAL DEVICE OPERATION
Code
$D0
$0C
$D9
$50
$00
$04
$08
...
34704
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