ACT8890 - Active-Semi

ACT8890
Rev 1, 05-Sep-13
Advanced PMU for Portable Handheld Equipment
FEATURES
GENERAL DESCRIPTION
•
•
•
•
•
•
The ACT8890 is a complete, cost effective, highlyefficient ActivePMUTM power management solution,
for portable handheld equipment such as
Smartphones, Mobile Internet Devices (MID),
eBooks and etc.
Three Step-Down DC/DC Converters
Four Low-Dropout Linear Regulators
I2CTM Serial Interface
Advanced Enable/Disable Sequencing Controller
This device features three step-down DC/DC
converters and four low-noise, low-dropout linear
regulators.
Minimal External Components
Tiny 4×4mm TQFN44-32 Package
− 0.75mm Package Height
− Pb-Free and RoHS Compliant
The three DC/DC converters utilize a highefficiency, fixed-frequency (2MHz), current-mode
PWM control architecture that requires a minimum
number of external components. Two DC/DCs are
capable of supplying up to 1150mA of output
current, while the third supports up to 1300mA. All
four low-dropout linear regulators are highperformance, low-noise, regulators that supply up to
320mA each.
The ACT8890 is available in a compact, Pb-Free
and RoHS-compliant TQFN44-32 package.
SYSTEM BLOCK DIAGRAM
ActivePMU
TM
Innovative PowerTM
-1Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
TABLE OF CONTENTS
General Information ..................................................................................................................................... p. 01
Functional Block Diagram ............................................................................................................................ p. 03
Ordering Information .................................................................................................................................... p. 04
Pin Configuration ......................................................................................................................................... p. 04
Pin Descriptions ........................................................................................................................................... p. 05
Absolute Maximum Ratings ......................................................................................................................... p. 07
I2C Interface Electrical Characteristics ........................................................................................................ p. 08
Global Register Map .................................................................................................................................... p. 09
Register and Bit Descriptions ...................................................................................................................... p. 10
System Control Electrical Characteristics.................................................................................................... p. 13
Step-Down DC/DC Electrical Characteristics .............................................................................................. p. 14
Low-Noise LDO Electrical Characteristics ................................................................................................... p. 15
Typical Performance Characteristics ........................................................................................................... p. 16
System control information .......................................................................................................................... p. 21
Control Signals ................................................................................................................................. p. 21
Functional Description ................................................................................................................................. p. 22
I2C Interface ..................................................................................................................................... p. 22
Thermal Shutdown ........................................................................................................................... p. 22
Step-Down DC/DC Regulators .................................................................................................................... p. 23
General Description.......................................................................................................................... p. 23
100% Duty Cycle Operation ............................................................................................................. p. 23
Synchronous Rectification ................................................................................................................ p. 23
Soft-Start .......................................................................................................................................... p. 23
Compensation .................................................................................................................................. p. 23
Configuration Options....................................................................................................................... p. 23
Output OK[ ] .................................................................................................................................... p. 24
PCB Layout Considerations ............................................................................................................. p. 24
Low-Noise, Low-Dropout Linear Regulators................................................................................................ p. 25
General Description.......................................................................................................................... p. 25
Output Current Limit ......................................................................................................................... p. 25
Compensation .................................................................................................................................. p. 25
Configuration Options....................................................................................................................... p. 25
Output OK[ ] .................................................................................................................................... p. 25
PCB Layout Considerations ............................................................................................................. p. 25
TQFN44-32 Package Outline and Dimensions ........................................................................................... p. 26
Innovative PowerTM
-2Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
FUNCTIONAL BLOCK DIAGRAM
VP1
To Battery
ACT8890
SW1
OUT1
OUT1
OUT1
nRSTO
GP1
VP2
To Battery
SW2
OUT2
ON1
OUT2
GP2
ON2
VP3
ON3
To Battery
SW3
OUT3
ON45
OUT3
System
Control
GP3
ON6
INL45
ON7
REG4
LDO
SCL
SDA
Serial
Interface
REG5
LDO
VDDREF
REFBP
OUT4
OUT4
OUT5
OUT5
INL67
To Battery
Reference
GA
REG6
LDO
REG7
LDO
To Battery
To Battery
OUT6
OUT6
OUT7
OUT7
EP
Innovative PowerTM
-3Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
ORDERING INFORMATION
PART NUMBER
VOUT1
VOUT2
VOUT3
VOUT4
VOUT5
VOUT6
VOUT7
PACKAGE
PINS
TEMPERATURE
RANGE
ACT8890Q4I133-T
3.3V
1.3V
1.3V
1.2V
1.2V
1.2V
3.3V
TQFN44-32
32
-40°C to +85°C
ACT8890Q4I233-T
1.2V
1.5V
1.2V
1.2V
3.0V
3.0V
1.8V
TQFN44-32
32
-40°C to +85°C
ACT8890Q4I234-T
1.8V
3.0V
1.2V
1.2V
3.0V
3.3V
2.5V
TQFN44-32
32
-40°C to +85°C
: All Active-Semi components are RoHS Compliant and with Pb-free plating unless specified differently. The term Pb-free means
semiconductor products that are in compliance with current RoHS (Restriction of Hazardous Substances) standards.
: Standard product options are identified in this table. Contact factory for custom options, minimum order quantity is 12,000 units.
PIN CONFIGURATION
REFBP
VP1
SW1
GP1
GP2
SW2
VP2
NC2
ON6
ON7
nRSTO
ON45
ON1
GP3
SW3
VP3
TOP VIEW
Thin - QFN (TQFN44-32)
Innovative PowerTM
-4Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
PIN DESCRIPTIONS
PIN
NAME
DESCRIPTION
1
OUT1
Output Feedback Sense for REG1. Connect this pin directly to the output node to connect the
internal feedback network to the output voltage.
2
GA
Analog Ground. Connect GA directly to a quiet ground node. Connect GA, GP1,GP2 and GP3
together at a single point as close to the IC as possible.
3
OUT4
Output Voltage for REG4. Capable of delivering up to 320mA of output current. Connect a 3.3µF
ceramic capacitor from OUT4 to GA. The output is discharged to GA with 1.5kΩ resistor when
disabled.
4
OUT5
Output Voltage for REG5. Capable of delivering up to 320mA of output current. Connect a 3.3µF
ceramic capacitor from OUT5 to GA. The output is discharged to GA with 1.5kΩ resistor when
disabled.
5
INL45
Power Input for REG4 and REG5. Bypass to GA with a high quality ceramic capacitor placed as
close to the IC as possible.
6
INL67
Power Input for REG6 and REG7. Bypass to GA with a high quality ceramic capacitor placed as
close to the IC as possible.
7
OUT6
Output Voltage for REG6. Capable of delivering up to 320mA of output current. Connect a 3.3µF
ceramic capacitor from OUT6 to GA. The output is discharged to GA with 1.5kΩ resistor when
disabled.
8
OUT7
Output Voltage for REG7. Capable of delivering up to 320mA of output current. Connect a 3.3µF
ceramic capacitor from OUT7 to GA. The output is discharged to GA with 1.5kΩ resistor when
disabled.
9
ON6
Enable Input for REG6. Drive to VP1 or a logic high to enable REG6. Drive to GA to disable.
10
ON7
Enable Input for REG7. Drive to VP1 or a logic high to enable REG7. Drive to GA to disable.
11
nRSTO
12
ON45
Enable Input for REG4 and REG5. Drive to VP1 or a logic high to enable REG4 and REG5. Drive
to GA to disable.
13
ON1
Enable Input for REG1. Drive to VP1 or a logic high to enable REG1. Drive to GA to disable.
14
GP3
Power Ground for REG3. Connect GA, GP1, GP2, and GP3 together at a single point as close to
the IC as possible.
15
SW3
Switching Node Output for REG3. Connect this pin to the switching end of the inductor.
16
VP3
Power Input for REG3. Bypass to GP3 with a high quality ceramic capacitor placed as close to the
IC as possible.
17
ON3
Enable Input for REG3. Drive to VP1 or a logic high to enable REG3. Drive to GA to disable.
18
NC1
Not Connected. Not internally connected.
19
OUT3
20
ON2
Enable Input for REG2. Drive to VP1 or a logic high to enable REG2. Drive to GA to disable.
21
SCL
Clock Input for I2C Serial Interface.
22
SDA
Data Input for I2C Serial Interface. Data is read on the rising edge of SCL.
Active Low Reset Output. See the nRSTO Output section for more information.
Output Feedback Sense for REG3. Connect this pin directly to the output node to connect the
internal feedback network to the output voltage.
Innovative PowerTM
-5Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
PIN DESCRIPTIONS CONT’D
PIN
23
NAME
DESCRIPTION
Power supply for the internal reference. Connect this pin directly to the system power supply.
VDDREF Bypass VDDREF to GA with a 1µF capacitor placed as close to the IC as possible. Star
connection with VP1, VP2 and VP3 preferred.
Output Feedback Sense for REG2. Connect this pin directly to the output node to connect the
internal feedback network to the output voltage.
24
OUT2
25
NC2
Not Connected. Not internally connected.
26
VP2
Power Input for REG2 and System Control. Bypass to GP2 with a high quality ceramic capacitor
placed as close to the IC as possible.
27
SW2
Switching Node Output for REG2. Connect this pin to the switching end of the inductor.
28
GP2
Power Ground for REG2. Connect GA, GP1,GP2 and GP3 together at a single point as close to
the IC as possible.
29
GP1
Power Ground for REG1. Connect GA, GP1,GP2 and GP3 together at a single point as close to
the IC as possible.
30
SW1
Switching Node Output for REG1. Connect this pin to the switching end of the inductor.
31
VP1
Power Input for REG1. Bypass to GP1 with a high quality ceramic capacitor placed as close to
the IC as possible.
32
REFBP
EP
EP
Reference Bypass. Connect a 0.047μF ceramic capacitor from REFBP to GA. This pin is
discharged to GA in shutdown.
Exposed Pad. Must be soldered to ground on PCB.
Innovative PowerTM
-6Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
ABSOLUTE MAXIMUM RATINGS
PARAMETER
VALUE
UNIT
VP1 to GP1, VP2 to GP2, VP3 to GP3
-0.3 to + 6
V
INL, VDDREF to GA
-0.3 to + 6
V
-0.3 to (VVDDREF + 0.3)
V
-0.3 to + 6
V
SW1, OUT1 to GP1
-0.3 to (VVP1 + 0.3)
V
SW2, OUT2 to GP2
-0.3 to (VVP2 + 0.3)
V
SW3, OUT3 to GP3
-0.3 to (VVP3 + 0.3)
V
OUT4, OUT5, OUT6, OUT7 to GA
-0.3 to (VINL + 0.3)
V
-0.3 to + 0.3
V
27.5
°C/W
Operating Ambient Temperature
-40 to 85
°C
Maximum Junction Temperature
125
°C
-65 to 150
°C
300
°C
SCL, SDA, REFBP, ON1, ON2, ON3, ON45, ON6, ON7 to GA
nRSTO to GA
GP1, GP2, GP3 to GA
Junction to Ambient Thermal Resistance (θJA)
Storage Temperature
Lead Temperature (Soldering, 10 sec)
: Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods may
affect device reliability.
Innovative PowerTM
-7Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
I2C INTERFACE ELECTRICAL CHARACTERISTICS
(VVP1 = VVP2 = VVP3 = 3.6V, TA = 25°C, unless otherwise specified.)
PARAMETER
TEST CONDITIONS
MIN
SCL, SDA Input Low
VVDDREF = 3.1V to 5.5V, TA = -40ºC to 85ºC
SCL, SDA Input High
VVDDREF = 3.1V to 5.5V, TA = -40ºC to 85ºC
TYP
UNIT
0.35
V
1.55
V
SDA Leakage Current
SCL Leakage Current
1
SDA Output Low
MAX
IOL = 5mA
1
µA
2
µA
0.35
V
SCL Clock Period, tSCL
1.5
µs
SDA Data Setup Time, tSU
100
ns
SDA Data Hold Time, tHD
300
ns
Start Setup Time, tST
For Start Condition
100
ns
Stop Setup Time, tSP
For Stop Condition
100
ns
Figure 1:
I2C Compatible Serial Bus Timing
tSCL
SCL
tST
tHD
tSU
tSP
SDA
Start
condition
Innovative PowerTM
-8Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
Stop
condition
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
GLOBAL REGISTER MAP
BITS
OUTPUT ADDRESS
SYS
SYS
0x00
0x01
REG1
0x20
REG1
0x22
REG2
REG2
REG3
REG3
REG4
REG4
REG5
REG5
REG6
REG6
REG7
REG7
0x30
0x32
0x40
0x42
0x50
0x51
0x54
0x55
0x60
0x61
0x64
0x65
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
NAME
DEFAULT
D7
D6
D5
D4
D3
D2
D1
D0
TRST
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
0
1
1
1
0
1
0
R
Reserved
Reserved
Reserved
Reserved
SCRATCH SCRATCH SCRATCH SCRATCH
0
0
0
0
0
0
0
0
Reserved
Reserved
VSET[5]
VSET[4]
VSET[3]
VSET[2]
VSET[1]
VSET[0]
0
0
1
1
1
0
0
1
ON
PHASE
MODE
Reserved
Reserved
Reserved
Reserved
OK
0
0
0
0
0
0
0
R
Reserved
Reserved
VSET[5]
VSET[4]
VSET[3]
VSET[2]
VSET[1]
VSET[0]
0
0
0
1
1
0
1
0
ON
PHASE
MODE
Reserved
Reserved
Reserved
Reserved
OK
0
0
0
0
0
0
0
R
Reserved
Reserved
VSET[5]
VSET[4]
VSET[3]
VSET[2]
VSET[1]
VSET[0]
0
0
0
1
1
0
1
0
ON
Reserved
MODE
Reserved
Reserved
Reserved
Reserved
OK
0
0
0
0
0
0
0
R
Reserved
Reserved
VSET[5]
VSET[4]
VSET[3]
VSET[2]
VSET[1]
VSET[0]
0
0
0
1
1
0
0
0
ON
DIS
LOWIQ
Reserved
Reserved
Reserved
Reserved
OK
0
1
0
0
0
0
0
R
Reserved
Reserved
VSET[5]
VSET[4]
VSET[3]
VSET[2]
VSET[1]
VSET[0]
0
0
0
1
1
0
0
0
ON
DIS
LOWIQ
Reserved
Reserved
Reserved
Reserved
OK
0
1
0
0
0
0
0
R
Reserved
Reserved
VSET[5]
VSET[4]
VSET[3]
VSET[2]
VSET[1]
VSET[0]
0
0
0
1
1
0
0
0
ON
DIS
LOWIQ
Reserved
Reserved
Reserved
Reserved
OK
0
1
0
0
0
0
0
R
Reserved
Reserved
VSET[5]
VSET[4]
VSET[3]
VSET[2]
VSET[1]
VSET[0]
0
0
1
1
1
0
0
1
ON
DIS
LOWIQ
Reserved
Reserved
Reserved
Reserved
OK
0
1
0
0
0
0
0
R
: Default values of ACT8890Q4I133-T.
Innovative PowerTM
-9Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
REGISTER AND BIT DESCRIPTIONS
Table 1:
Global Register Map
OUTPUT ADDRESS BIT
NAME
ACCESS
DESCRIPTION
Reset Timer Setting. Defines the reset time-out threshold. Reset
time-out is 65ms when value is 1, reset time-out is 260ms when
value is 0. See nRSTO Output section for more information.
SYS
0x00
[7]
TRST
R/W
SYS
0x00
[6:0]
-
R
Reserved.
SYS
0x01
[7:4]
-
R/W
Reserved.
SYS
0x01
[3:0]
SCRATCH
R/W
Scratchpad Bits. Non-functional bits, maybe be used by user to
store system status information. Volatile bits, which are cleared
upon system shutdown.
REG1
0x20
[7:6]
-
R
REG1
0x20
[5:0]
VSET
R/W
Primary Output Voltage Selection. See the Output Voltage
Programming section for more information.
REG1
0x22
[7]
ON
R/W
Regulator Enable Bit. Set bit to 1 to enable the regulator, clear bit
to 0 to disable the regulator.
REG1
0x22
[6]
PHASE
R/W
Regulator Phase Control. Set bit to 1 for regulator to operate
180° out of phase with the oscillator, clear bit to 0 for regulator to
operate in phase with the oscillator.
REG1
0x22
[5]
MODE
R/W
Regulator Mode Select. Set bit to 1 for fixed-frequency PWM
under all load conditions, clear bit to 0 to transition to powersavings mode under light-load conditions.
REG1
0x22
[4:1]
-
R
Reserved.
REG1
0x22
[0]
OK
R
Regulator Power-OK Status. Value is 1 when output voltage
exceeds the power-OK threshold, value is 0 otherwise.
REG2
0x30
[7:6]
-
R
Reserved.
REG2
0x30
[5:0]
VSET
R/W
Primary Output Voltage Selection. See the Output Voltage
Programming section for more information.
REG2
0x32
[7]
ON
R/W
Regulator Enable Bit. Set bit to 1 to enable the regulator, clear bit
to 0 to disable the regulator.
REG2
0x32
[6]
PHASE
R/W
Regulator Phase Control. Set bit to 1 for regulator to operate
180° out of phase with the oscillator, clear bit to 0 for regulator to
operate in phase with the oscillator.
Reserved.
Innovative PowerTM
- 10 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
REGISTER AND BIT DESCRIPTIONS CONT’D
OUTPUT
ADDRESS
BIT
NAME
ACCESS
DESCRIPTION
Regulator Mode Select. Set bit to 1 for fixed-frequency PWM
under all load conditions, clear bit to 0 to transition to powersavings mode under light-load conditions.
REG2
0x32
[5]
MODE
R/W
REG2
0x32
[4:1]
-
R
Reserved.
REG2
0x32
[0]
OK
R
Regulator Power-OK Status. Value is 1 when output voltage
exceeds the power-OK threshold, value is 0 otherwise.
REG3
0x40
[7:6]
-
R
Reserved.
REG3
0x40
[5:0]
VSET
R/W
Primary Output Voltage Selection. See the Output Voltage
Programming section for more information.
REG3
0x42
[7]
ON
R/W
Regulator Enable Bit. Set bit to 1 to enable the regulator, clear
bit to 0 to disable the regulator.
REG3
0x42
[6]
-
R
REG3
0x42
[5]
MODE
R/W
REG3
0x42
[4:1]
-
R
Reserved.
REG3
0x42
[0]
OK
R
Regulator Power-OK Status. Value is 1 when output voltage
exceeds the power-OK threshold, value is 0 otherwise.
REG4
0x50
[7:6]
-
R
Reserved.
REG4
0x50
[5:0]
VSET
R/W
Output Voltage Selection. See the Output Voltage
Programming section for more information.
REG4
0x51
[7]
ON
R/W
Regulator Enable Bit. Set bit to 1 to enable the regulator, clear
bit to 0 to disable the regulator.
Reserved.
Regulator Mode Select. Set bit to 1 for fixed-frequency PWM
under all load conditions, clear bit to 0 to transit to powersavings mode under light-load conditions.
REG4
0x51
[6]
DIS
R/W
Output Discharge Control. When activated, discharges LDO
output to GA through 1.5kΩ when in shutdown. Set bit to 1 to
enable output voltage discharge in shutdown, clear bit to 0 to
disable this function.
REG4
0x51
[5]
LOWIQ
R/W
LDO Low-IQ Mode Control. Set bit to 1 for low-power
operating mode, clear bit to 0 for normal mode.
REG4
0x51
[4:1]
-
R
Reserved.
REG4
0x51
[0]
OK
R
Regulator Power-OK Status. Value is 1 when output voltage
exceeds the power-OK threshold, value is 0 otherwise.
REG5
0x54
[7:6]
-
R
Reserved.
REG5
0x54
[5:0]
VSET
R/W
Output Voltage Selection. See the Output Voltage
Programming section for more information.
REG5
0x55
[7]
ON
R/W
Regulator Enable Bit. Set bit to 1 to enable the regulator, clear
bit to 0 to disable the regulator.
REG5
0x55
[6]
DIS
R/W
Output Discharge Control. When activated, discharges LDO
output to GA through 1.5kΩ when in shutdown. Set bit to 1 to
enable output voltage discharge in shutdown, clear bit to 0 to
disable this function.
REG5
0x55
[5]
LOWIQ
R/W
LDO Low-IQ Mode Control. Set bit to 1 for low-power
operating mode, clear bit to 0 for normal mode.
REG5
0x55
[4:1]
-
R
Reserved.
REG5
0x55
[0]
OK
R
Regulator Power-OK Status. Value is 1 when output voltage
exceeds the power-OK threshold, value is 0 otherwise.
Innovative PowerTM
- 11 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
REGISTER AND BIT DESCRIPTIONS CONT’D
OUTPUT
ADDRESS
BIT
NAME
ACCESS
REG6
0x60
[7:6]
-
R
DESCRIPTION
Reserved.
REG6
0x60
[5:0]
VSET
R/W
Output Voltage Selection. See the Output Voltage
Programming section for more information.
REG6
0x61
[7]
ON
R/W
Regulator Enable Bit. Set bit to 1 to enable the regulator,
clear bit to 0 to disable the regulator.
REG6
0x61
[6]
DIS
R/W
Output Discharge Control. When activated, discharges LDO
output to GA through 1.5kΩ when in shutdown. Set bit to 1 to
enable output voltage discharge in shutdown, clear bit to 0 to
disable this function.
REG6
0x61
[5]
LOWIQ
R/W
LDO Low-IQ Mode Control. Set bit to 1 for low-power
operating mode, clear bit to 0 for normal mode.
REG6
0x61
[4:1]
-
R
Reserved.
REG6
0x61
[0]
OK
R
Regulator Power-OK Status. Value is 1 when output voltage
exceeds the power-OK threshold, value is 0 otherwise.
REG7
0x64
[7:6]
-
R
Reserved.
REG7
0x64
[5:0]
VSET
R/W
Output Voltage Selection. See the Output Voltage
Programming section for more information.
REG7
0x65
[7]
ON
R/W
Regulator Enable Bit. Set bit to 1 to enable the regulator,
clear bit to 0 to disable the regulator.
REG7
0x65
[6]
DIS
R/W
Output Discharge Control. When activated, discharges LDO
output to GA through 1.5kΩ when in shutdown. Set bit to 1 to
enable output voltage discharge in shutdown, clear bit to 0 to
disable this function.
REG7
0x65
[5]
LOWIQ
R/W
LDO Low-IQ Mode Control. Set bit to 1 for low-power
operating mode, clear bit to 0 for normal mode.
REG7
0x65
[4:1]
-
R
Reserved.
REG7
0x65
[0]
OK
R
Regulator Power-OK Status. Value is 1 when output voltage
exceeds the power-OK threshold, value is 0 otherwise.
Innovative PowerTM
- 12 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
SYSTEM CONTROL ELECTRICAL CHARACTERISTICS
(VVP1 = VVP2 = VVP3 = 3.6V, TA = 25°C, unless otherwise specified.)
PARAMETER
TEST CONDITIONS
Input Voltage Range
MIN
TYP
2.7
MAX
UNIT
5.5
V
2.65
V
UVLO Threshold Voltage
VVDDREF Rising
UVLO Hysteresis
VVDDREF Falling
200
mV
Supply Current
REG1, REG2, REG3, REG4, REG5,
REG6 and REG7 Enabled
420
µA
Shutdown Supply Current
All Regulators Disabled
1.5
3.0
µA
2
2.2
MHz
Oscillator Frequency
Logic High Input Voltage
2.2
1.8
2.45
1.4
1
V
Logic Low Input Voltage
Leakage Current
Low Level Output Voltage
VnRSTO = 4.2V
2
nRSTO. ISINK = 5mA
nRSTO Delay
Thermal Shutdown Temperature
Temperature rising
Thermal Shutdown Hysteresis
0.4
V
1
µA
0.35
V
260
ms
160
°C
20
°C
: ON1, ON2, ON3, ON45, ON6, ON7 are logic inputs.
2: nRSTO are open drain outputs.
3: Typical value shown. Actual value may vary from 227.9ms to 291.2ms.
Innovative PowerTM
- 13 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
STEP-DOWN DC/DC ELECTRICAL CHARACTERISTICS
(VVP1 = VVP2 = VVP3 = 3.6V, TA = 25°C, unless otherwise specified.)
PARAMETER
CONDITIONS
Operating Voltage Range
MIN
TYP
2.7
5.5
V
2.7
V
Input Voltage Rising
UVLO Hysteresis
Input Voltage Falling
100
Quiescent Supply Current
Regulator Enabled
65
90
µA
Shutdown Current
VVP = 5.5V, Regulator Disabled
0
1
µA
mV
VOUT ≥ 1.2V, IOUT = 10mA
-1%
VNOM
1%
VOUT < 1.2V, IOUT = 10mA
-2%
VNOM
2%
Line Regulation
VVP = Max(VNOM1 +1, 3.2V) to 5.5V
Load Regulation
IOUT = 10mA to IMAX
Power Good Threshold
Power Good Hysteresis
Oscillator Frequency
2.6
UNIT
UVLO Threshold
Output Voltage Accuracy
2.5
MAX
V
0.15
%/V
0.0017
%/mA
VOUT Rising
93
%VNOM
VOUT Falling
2
%VNOM
2
VOUT ≥ 20% of VNOM
1.8
2
VOUT = 0V
2.2
MHz
500
kHz
Soft-Start Period
400
µs
Minimum On-Time
75
ns
REG1
Maximum Output Current
1.15
Current Limit
1.5
A
1.8
2.1
A
PMOS On-Resistance
ISW1 = -100mA
0.16
Ω
NMOS On-Resistance
ISW1 = 100mA
0.16
Ω
SW1 Leakage Current
VVP1 = 5.5V, VSW1 = 0 or 5.5V
0
1
µA
REG2
Maximum Output Current
1.15
Current Limit
1.5
PMOS On-Resistance
A
1.8
ISW2 = -100mA
0.16
NMOS On-Resistance
ISW2 = 100mA
0.16
SW2 Leakage Current
VVP2 = 5.5V, VSW2 = 0 or 5.5V
0
2.1
A
Ω
Ω
1
µA
REG3
Maximum Output Current
1.3
Current Limit
1.7
A
2.1
2.5
A
PMOS On-Resistance
ISW3 = -100mA
0.16
Ω
NMOS On-Resistance
ISW3 = 100mA
0.16
Ω
SW3 Leakage Current
VVP3 = 5.5V, VSW3 = 0 or 5.5V
0
1
µA
: VNOM refers to the nominal output voltage level for VOUT as defined by the Ordering Information section.
2: IMAX Maximum Output Current.
Innovative PowerTM
- 14 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
LOW-NOISE LDO ELECTRICAL CHARACTERISTICS
(VINL = 3.6V, COUT4 = COUT5 = COUT6 = COUT7 = 3.3µF, LOWIQ[ ] = [0], TA = 25°C, unless otherwise specified.)
PARAMETER
TEST CONDITIONS
Operating Voltage Range
Output Voltage Accuracy
Line Regulation
Load Regulation
Power Supply Rejection Ratio
Supply Current per Output
MIN
MAX
UNIT
5.5
V
2.5
VOUT ≥ 1.2V, TA = 25°C, IOUT = 10mA
-1%
VNOM
2%
VOUT < 1.2V, TA = 25°C, IOUT = 10mA
-2%
VNOM
4%
VINL = Max(VOUT + 0.5V, 3.6V) to 5.5V
LOWIQ[ ] = [0]
0.05
VINL = Max(VOUT + 0.5V, 3.6V) to 5.5V
LOWIQ[ ] = [1]
0.5
IOUT = 1mA to IMAX2
0.08
V
mV/V
V/A
f = 1kHz, IOUT = 20mA
75
f = 10kHz, IOUT = 20mA
65
Regulator Enabled, LOWIQ[ ] = [0]
37
60
Regulator Enabled, LOWIQ[ ] = [1]
31
52
0
1
Regulator Disabled
Soft-Start Period
TYP
dB
µA
VOUT = 2.9V
140
µs
Power Good Threshold
VOUT Rising
89
%
Power Good Hysteresis
VOUT Falling
3
%
Output Noise
IOUT = 20mA, f = 10Hz to 100kHz, VOUT =
1.2V
50
µVRMS
Discharge Resistance
LDO Disabled, DIS[ ] = 1
1.5
kΩ
REG4
Dropout Voltage
IOUT = 160mA, VOUT > 3.1V
Maximum Output Current
Current Limit
90
180
320
VOUT = 95% of regulation voltage
Stable COUT4 Range
mV
mA
400
mA
3.3
20
µF
280
mV
REG5
Dropout Voltage
IOUT = 160mA, VOUT > 3.1V
Maximum Output Current
Current Limit
VOUT = 95% of regulation voltage
Stable COUT5 Range
140
320
mA
400
mA
3.3
20
µF
180
mV
REG6
Dropout Voltage
IOUT = 160mA, VOUT > 3.1V
Maximum Output Current
Current Limit
90
320
VOUT = 95% of regulation voltage
Stable COUT6 Range
mA
400
mA
3.3
20
µF
280
mV
REG7
Dropout Voltage
IOUT = 160mA, VOUT > 3.1V
Maximum Output Current
Current Limit
VOUT = 95% of regulation voltage
Stable COUT7 Range
140
320
mA
400
mA
3.3
20
µF
: VNOM refers to the nominal output voltage level for VOUT as defined by the Ordering Information section.
2: IMAX Maximum Output Current.
3: Dropout Voltage is defined as the differential voltage between input and output when the output voltage drops 100mV below the
regulation voltage (for 3.1V output voltage or higher).
: LDO current limit is defined as the output current at which the output voltage drops to 95% of the respective regulation voltage.
Under heavy overload conditions the output current limit folds back by 30% (typ)
Innovative PowerTM
- 15 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
TYPICAL PERFORMANCE CHARACTERISTICS
(VVP1 = VVP2 = VVP3 = 3.6V, TA = 25°C, unless otherwise specified.)
Frequency vs. Temperature
VREF vs. Temperature
0
-0.42
-20
0
20
40
60
80
100
1.5
1
0.5
0
-0.5
Typical VREF=1.2V
-0.84
-40
2
Frequency (%)
VREF (%)
0.42
2.5
ACT8890-002
ACT8890-001
0.84
Typical Oscillator Frequency=2MHz
-1
-40
120
-20
0
20
40
Temperature (°C)
Temperature (°C)
ON1 Startup Sequence
ON2 Startup Sequence
60
ACT8890-004
ACT8890-003
CH1
80 85
CH1
CH2
CH2
CH3
CH1: ON2, 2V/div
CH2: VOUT2, 500mV/div
TIME: 400µs/div
CH1: ON1, 2V/div
CH2: VOUT1, 2V/div
CH3: VnRSTO, 2V/div
TIME: 40ms/div
ON3 Startup Sequence
ON4, 5 Startup Sequence
ACT8890-006
ACT8890-005
CH1
CH1
CH2
CH2
CH3
CH1: ON3, 2V/div
CH2: VOUT3, 500mV/div
TIME: 400µs/div
Innovative PowerTM
- 16 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
CH1: ON4, 5, 2V/div
CH2: VOUT4, 500mV/div
CH3: VOUT5, 500mV/div
TIME: 100µs//div
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Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(TA = 25°C, unless otherwise specified.)
ON6 startup sequence
ON7 startup sequence
ACT8890-008
ACT8890-007
CH1
CH1
CH2
CH2
CH1: ON6, 2V/div
CH2: VOUT6, 500mV/div
TIME: 100µs/div
CH1: ON7, 2V/div
CH2: VOUT7, 1V/div
TIME: 100µs/div
REG1 Efficiency vs. Output Current
REG2 Efficiency vs. Output Current
Efficiency (%)
80
VIN = 3.6V
VIN=5.0V
VIN = 4.2V
60
VOUT = 1.3V
80
Efficiency (%)
VOUT = 3.3V
100
40
ACT8890-010
ACT8890-009
100
VIN=5.0V
VIN = 3.6V
60
VIN = 4.2V
40
20
20
0
0
1
10
100
10
1
1000
100
1000
Output Current (mA)
Output Current (mA)
REG3 Efficiency vs. Output Current
100
Efficiency (%)
80
VIN = 3.6V
ACT8890-011
VOUT = 1.3V
VIN=5.0V
VIN = 4.2V
60
40
20
0
1
10
100
1000
Output Current (mA)
Innovative PowerTM
- 17 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(TA = 25°C, unless otherwise specified.)
REG1 Output Voltage vs. Temperature
REG2 Output Voltage vs. Temperature
Output Voltage (V)
3.306
3.302
3.298
3.294
3.290
-40
-20
0
20
40
60
80
100
VOUT2 = 1.3V
ILOAD = 100mA
1.306
Output Voltage (V)
VOUT1 = 3.3V
ILOAD = 100mA
1.310
1.302
1.298
1.294
1.290
-40
120
-20
0
40
60
80
100
120
REG1, 2, 3 MOSFET Resistance
REG3 Output Voltage vs. Temperature
1.298
ILOAD = 100mA
300
250
RDSON (mΩ)
1.302
ACT8890-015
350
ACT8890-014
VOUT2 = 1.3V
ILOAD = 100mA
1.306
Output Voltage (V)
20
Temperature (°C)
Temperature (°C)
1.310
ACT8890-013
ACT8890-012
3.310
200
PMOS
NMOS
150
100
1.294
1.290
-40
50
0
-20
0
20
40
60
80
100
120
Temperature (°C)
Innovative PowerTM
- 18 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
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Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(TA = 25°C, unless otherwise specified.)
REG4, 5, 6 Output Voltage vs. Output Current
1.24
REG4, REG5, REG6
1.2
1.16
1.12
1.08
3.58
Output Voltage (V)
Output Voltage (V)
1.28
REG7 Output Voltage vs. Output Current
3.66
ACT8890-017
ACT8890-016
1.32
3.5
3.42
REG7
3.34
3.26
3.18
3.1
1.04
3.02
1
0
50
100
150
200
250
300
0
400
50
Dropout Voltage vs. Output Current
100
50
VIN = 3.3V
0
150
200
250
300
350
400
Output Current (mA)
Innovative PowerTM
- 19 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
300
400
350
300
Dropout Voltage (mV)
Dropout Voltage (mV)
REG4, REG6
100
250
ACT8890-019
ACT8890-018
200
50
200
Dropout Voltage vs. Output Current
250
0
150
Output Current (mA)
Output Current (mA)
150
100
250
REG5, REG7
200
150
100
50
0
VIN = 3.3V
0
50
100
150
200
250
300
350
400
Output Current (mA)
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Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(TA = 25°C, unless otherwise specified.)
Output Voltage vs. Temperature
2.50
ESR (Ω)
Output Voltage (V)
3.00
2.00
1.50
1
REG4, REG5, REG6
ACT8890-021
REG7
3.50
Region of Stable COUT ESR vs. Output Current
ACT8890-020
4.00
0.1
Stable ESR
1.00
0.50
0.01
0
-40
-20
0
20
40
60
80
100
120
0
Temperature (°C)
50
100
150
200
250
Output Current (mA)
LDO Output Voltage Noise
ACT8890-022
CH1
CH1: VOUTx, 200µV/div (AC COUPLED)
TIME: 200ms/div
Innovative PowerTM
- 20 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
SYSTEM CONTROL INFORMATION
Control Signals
nRSTO Output
Enable Inputs
ON1, ON2, ON3, ON45, ON6 and ON7 are
independent logic inputs for the regulators as
shown in Table 2. Drive to logic high to enable the
corresponding regulator(s); Drive to GA to disable.
nRSTO is an open-drain output which asserts low
when any one or more of the regulator reaches the
power-OK threshold. nRSTO remains low until the
260ms reset timeout period expires. Connect a
10kΩ or greater pull-up resistor from nRSTO to an
appropriate voltage supply (typically OUT1).
Table 2:
Control Pins
PIN NAME
REGULATOR(S)
ON1
OUT1
ON2
OUT2
ON3
OUT3
ON45
OUT4, OUT5
ON6
OUT6
ON7
OUT7
Figure 2:
Enable/Disable Sequence
Innovative PowerTM
- 21 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
FUNCTIONAL DESCRIPTION
I2C Interface
The ACT8890 features an I2C interface that allows
advanced programming capability to enhance overall
system performance. To ensure compatibility with a
wide range of system processors, the I2C interface
supports clock speeds of up to 400kHz (“Fast-Mode”
operation) and uses standard I2C commands. I2C
write-byte commands are used to program the
ACT8890, and I2C read-byte commands are used to
read the ACT8890’s internal registers. The ACT8890
always operates as a slave device, and is addressed
using a 7-bit slave address followed by an eighth bit,
which indicates whether the transaction is a readoperation or a write-operation, [1011011x].
SDA is a bi-directional data line and SCL is a clock
input. The master device initiates a transaction by
issuing a START condition, defined by SDA
transitioning from high to low while SCL is high. Data
is transferred in 8-bit packets, beginning with the
MSB, and is clocked-in on the rising edge of SCL.
Each packet of data is followed by an “Acknowledge”
(ACK) bit, used to confirm that the data was
transmitted successfully.
For more information regarding the I2C 2-wire serial
interface, go to the NXP website: http://www.nxp.com.
Thermal Shutdown
The ACT8890 integrates thermal shutdown
protection circuitry to prevent damage resulting from
excessive thermal stress, as may be encountered
under fault conditions. This circuitry disables all
regulators if the ACT8890 die temperature exceeds
160°C, and prevents the regulators from being
enabled until the IC temperature drops by 20°C (typ).
Innovative PowerTM
- 22 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
STEP-DOWN DC/DC REGULATORS
General Description
The ACT8890 features three synchronous, fixedfrequency, current-mode PWM step down converters
that achieve peak efficiencies of up to 97%. REG3 is
capable of supplying up to 1300mA of output
current, while REG1 and REG2 support up to
1150mA. These regulators operate with a fixed
frequency of 2MHz, minimizing noise in sensitive
applications and allowing the use of small external
components.
100% Duty Cycle Operation
Each regulator is capable of operating at up to 100%
duty cycle. During 100% duty-cycle operation, the
high-side power MOSFET is held on continuously,
providing a direct connection from the input to the
output (through the inductor), ensuring the lowest
possible dropout voltage in battery powered
applications.
Synchronous Rectification
REG1, REG2, and REG3 each feature integrated nchannel synchronous rectifiers, maximizing efficiency
and minimizing the total solution size and cost by
eliminating the need for external rectifiers.
Soft-Start
When enabled, each output voltages tracks an
internal 400μs soft-start ramp, minimizing input
current during startup and allowing each regulator to
power up in a smooth, monotonic manner that is
independent of output load conditions.
Compensation
Each buck regulator utilizes current-mode control and
a proprietary internal compensation scheme to
simultaneously simplify external component selection
and optimize transient performance over its full
operating range. No compensation design is
required; simply follow a few simple guidelines
described below when choosing external
components.
Input Capacitor Selection
The input capacitor reduces peak currents and noise
induced upon the voltage source. A 4.7μF ceramic
capacitor is recommended for each regulator in most
applications.
Output Capacitor Selection
For most applications, 22μF ceramic output
capacitors are recommended for REG1, REG2 and
REG3.
Despite the advantages of ceramic capacitors, care
must be taken during the design process to ensure
stable operation over the full operating voltage and
temperature range. Ceramic capacitors are available
in a variety of dielectrics, each of which exhibits
different characteristics that can greatly affect
performance over their temperature and voltage
ranges.
Two of the most common dielectrics are Y5V and
X5R. Whereas Y5V dielectrics are inexpensive and
can provide high capacitance in small packages, their
capacitance varies greatly over their voltage and
temperature ranges and are not recommended for
DC/DC applications. X5R and X7R dielectrics are
more suitable for output capacitor applications, as
their characteristics are more stable over their
operating ranges, and are highly recommended.
Inductor Selection
REG1, REG2, and REG3 utilize current-mode control
and a proprietary internal compensation scheme to
simultaneously simplify external component selection
and optimize transient performance over their full
operating range. These devices were optimized for
operation with 2.2μH inductors, although inductors in
the 1.5μH to 3.3μH range can be used. Choose an
inductor with a low DC-resistance, and avoid inductor
saturation by choosing inductors with DC ratings that
exceed the maximum output current by at least 30%.
Configuration Options
Output Voltage Programming
Each regulator powers up and regulates to its default
output voltage. Once the system is enabled, each
regulator's output voltage may be independently
programmed to a different value, typically in order to
minimize the power consumption of the
microprocessor during some operating modes.
Program the output voltages via the I2C serial
interface by writing to the regulator's VSET[-] register
as shown in Table 4.
Enable / Disable Control
During normal operation, each buck may be enabled
or disabled via the I2C interface by writing to that
regulator's ON[ ] bit. The regulator accept rising or
falling edge of ON[ ] bit as on/off signal. To enable
the regulator, clear ON[ ] to 0 first then set to 1. To
disable the regulator, set ON[ ] to 1 first then clear it
to 0.
Operating Mode
By default, REG1, REG2, and REG3 each operate in
fixed-frequency PWM mode at medium to heavy
Innovative PowerTM
- 23 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
loads, while automatically transitioning to a
proprietary power-saving mode at light loads in order
to maximize standby battery life. In applications
where low noise is critical, force fixed-frequency
PWM operation across the entire load current range,
at the expense of light-load efficiency, by setting the
MODE[ ] bit to 1.
Output OK[ ]
Each DC/DC features a power-OK status bit that can
be read by the system microprocessor via the I2C
interface. If an output voltage is lower than the powerOK threshold, typically 7% below the programmed
regulation voltage, that regulator's OK[ ] bit will be 0.
via if possible. The inductor, input filter capacitor, and
output filter capacitor should be connected as close
together as possible, with short, direct, and wide
traces. The ground nodes for each regulator's power
loop should be connected at a single point in a starground configuration, and this point should be
connected to the backside ground plane with multiple
via. The output node for each regulator should be
connected to its corresponding OUTx pin through the
shortest possible route, while keeping sufficient
distance from switching nodes to prevent noise
injection. Finally, the exposed pad should be directly
connected to the backside ground plane using
multiple via to achieve low electrical and thermal
resistance.
PCB Layout Considerations
High switching frequencies and large peak currents
make PC board layout an important part of step-down
DC/DC converter design. A good design minimizes
excessive EMI on the feedback paths and voltage
gradients in the ground plane, both of which can
result in instability or regulation errors.
Step-down DC/DCs exhibit discontinuous input
current, so the input capacitors should be placed as
close as possible to the IC, and avoiding the use of
Table 4:
REGx/VSET[ ] Output Voltage Setting
REGx/VSET[2:0]
REGx/VSET[5:3]
000
001
010
011
100
101
110
111
000
0.600
0.800
1.000
1.200
1.600
2.000
2.400
3.200
001
0.625
0.825
1.025
1.250
1.650
2.050
2.500
3.300
010
0.650
0.850
1.050
1.300
1.700
2.100
2.600
3.400
011
0.675
0.875
1.075
1.350
1.750
2.150
2.700
3.500
100
0.700
0.900
1.100
1.400
1.800
2.200
2.800
3.600
101
0.725
0.925
1.125
1.450
1.850
2.250
2.900
3.700
110
0.750
0.950
1.150
1.500
1.900
2.300
3.000
3.800
111
0.775
0.975
1.175
1.550
1.950
2.350
3.100
3.900
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Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
LOW-NOISE, LOW-DROPOUT LINEAR REGULATORS
General Description
REG4, REG5, REG6, and REG7 are low-noise,
low-dropout linear regulators (LDOs) that supply up
to 320mA. Each LDO has been optimized to
achieve low noise and high-PSRR, achieving more
than 65dB PSRR at frequencies up to 10kHz.
Output Current Limit
Each LDO contains current-limit circuitry featuring a
current-limit fold-back function. During normal and
moderate overload conditions, the regulators can
support more than their rated output currents.
During extreme overload conditions, however, the
current limit is reduced by approximately 30%,
reducing power dissipation within the IC.
Compensation
The LDOs are internally compensated and require
very little design effort, simply select input and
output capacitors according to the guidelines below.
Input Capacitor Selection
Each LDO requires a small ceramic input capacitor
to supply current to support fast transients at the
input of the LDO. Bypassing each INL pin to GA
with 1μF. High quality ceramic capacitors such as
X7R and X5R dielectric types are strongly
recommended.
Output Capacitor Selection
Each LDO requires a small 3.3μF ceramic output
capacitor for stability. For best performance, each
output capacitor should be connected directly
between the output and GA pins, as close to the
output as possible, and with a short, direct
connection. High quality ceramic capacitors such as
X7R and X5R dielectric types are strongly
recommended.
Configuration Options
Output Voltage Programming
By default, each LDO powers up and regulates to
its default output voltage. Once the system is
enabled, each output voltage may be independently
programmed to a different value by writing to the
regulator's VSET[-] register via the I2C serial
interface as shown in Table 4.
Enable / Disable Control
During normal operation, each LDO may be
enabled or disabled via the I2C interface by writing
to that LDO's ON[ ] bit. The regulator accept rising
or falling edge of ON[ ] bit as on/off signal. To
enable the regulator, clear ON[ ] to 0 first then set to
1. To disable the regulator, set ON[ ] to 1 first then
clear it to 0.
Output Discharge
Each of the ACT8890’s LDOs features an optional
output discharge function, which discharges the
output to ground through a 1.5kΩ resistance when
the LDO is disabled. This feature may be enabled
or disabled by setting DIS[-] via; set DIS[-] to 1 to
enable this function, clear DIS[-] to 0 to disable it.
Low-Power Mode
Each of ACT8890's LDOs features a LOWIQ[-] bit
which, when set to 1, reduces the LDO's quiescent
current by about 16%, saving power and extending
battery lifetime.
Output OK[ ]
Each LDO features a power-OK status bit that
be read by the system microprocessor via
interface. If an output voltage is lower than
power-OK threshold, typically 11% below
programmed regulation voltage, the value of
regulator's OK[-] bit will be 0.
PCB Layout Considerations
PCB Layout Considerations The ACT8890’s LDOs
provide good DC, AC, and noise performance over
a wide range of operating conditions, and are
relatively insensitive to layout considerations. When
designing a PCB, however, careful layout is
necessary to prevent other circuitry from degrading
LDO performance.
A good design places input and output capacitors
as close to the LDO inputs and output as possible,
and utilizes a star-ground configuration for all
regulators to prevent noise-coupling through
ground. Output traces should be routed to avoid
close proximity to noisy nodes, particularly the SW
nodes of the DC/DCs.
REFBP is a filtered reference noise, and internally
has a direct connection to the linear regulator
controller. Any noise injected onto REFBP will
directly affect the outputs of the linear regulators,
and therefore special care should be taken to
ensure that no noise is injected to the outputs via
REFBP. As with the LDO output capacitors, the
REFBP bypass capacitor should be placed as close
to the IC as possible, with short, direct connections
to the star-ground. Avoid the use of via whenever
possible. Noisy nodes, such as from the DC/DCs,
should be routed as far away from REFBP as
possible.
Innovative PowerTM
- 25 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
can
the
the
the
that
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
ACT8890
Rev 1, 05-Sep-13
TQF44-32 PACKAGE OUTLINE AND DIMENSIONS
D
D/ 2
SYMBOL
E/ 2
E
A3
MAX
MIN
MAX
A
0.700
0.800
0.028
0.031
A1
0.000
0.050
0.000
0.002
A3
D2
L
0.150
0.250
0.008
0.006
0.010
4.000 TYP
0.158 TYP
E
4.000 TYP
0.158 TYP
D2
2.550
2.800
0.100
0.110
E2
2.550
2.800
0.100
0.110
L
b
0.200
D
e
A1
DIMENSION IN
INCHES
MIN
b
A
DIMENSION IN
MILLIMETERS
R
0.400 TYP
0.250
0.450
0.250
0.016 TYP
0.010
0.018
0.010
e
E2
R
Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. Users should evaluate each
product to make sure that it is suitable for their applications. Active-Semi products are not intended or authorized for use
as critical components in life-support devices or systems. Active-Semi, Inc. does not assume any liability arising out of
the use of any product or circuit described in this datasheet, nor does it convey any patent license.
Active-Semi and its logo are trademarks of Active-Semi, Inc. For more information on this and other products, contact
sales@active-semi.com or visit http://www.active-semi.com.
is a registered trademark of Active-Semi.
Innovative PowerTM
- 26 Active-Semi Proprietary―For Authorized Recipients and Customers
ActivePMUTM is a trademark of Active-Semi.
I2CTM is a trademark of NXP.
www.active-semi.com
Copyright © 2013 Active-Semi, Inc.