SUMMIT SMM205NR03

SMM205
Preliminary Information1 (See Last Page)
Dual Channel Supply Voltage Marginer and Active DC Output Controller
FEATURES & APPLICATIONS
INTRODUCTION
• Extremely accurate (±0.1%) Active
DC Output Control (ADOC)
The SMM205 actively controls the output voltage level
of two DC/DC converters that use a Trim or VADJ/FB
pin to adjust the output. An Active DC Output Control
(ADOC) feature is used during normal operation to
maintain extremely accurate settings of supply
voltages and, during system test, to control margining
of the supplies using I2C commands. Total accuracy
with a ±0.1% external reference is ±0.2%, and ±0.5%
using the internal reference. The device can margin
supplies with either positive or negative trim pin control
within a range of 0.3V to VDD. The SMM105 supply
can be from 12V, 8V, 5V or 3.3V to as low as 2.7V to
accommodate any intermediate bus supply.
The voltage settings (margin high/low and nominal)
are programmed into nonvolatile memory through the
industry standard I2C 2-wire data bus. The I2C bus is
also used to enable margin high, margin low, ADOC or
normal operation. When margining, the SMM205
checks the voltage output of the converter and make
adjustments to the trim pin via a feedback loop to bring
the voltage to the margin setting. A margining status
register is set to indicate that the system is ready for
test. The SMM205 ADOC continues to monitor and
adjust the channel output at the specified level.
• ADOC Automatically adjusts supply output
voltage level under all load conditions
• Capable of margining supplies with trim inputs
using either positive or negative trim pin control
• Wide Margin/ADOC range from 0.3V to VDD
• Uses either an internal or external VREF
• Operates from any intermediate bus supply
from 8V to 15V and from 2.7V to 5.5V
• Programmable START and READY pins
• Two programmable general purpose monitor
sensors – UV and OV with FAULT Output Flag
• General Purpose 1k EEPROM with Write Protect
• I2C 2-wire serial bus for programming
configuration and monitoring status.
• 28 lead QFN package
Applications
• In-system test and control of Point-of-Load
(POL) Power Supplies for Multi-voltage
Processors, DSPs and ASICs
• Enterprise and edge routers, servers, Storage
Area Networks
2
IC
BUS
WP#
SDA
SCL
A0
A1
A2
VDD
6V to 15V
2.7V to 5.5V
Intermediate
Bus Voltage
(IBA
12VIN
SIMPLIFIED APPLICATIONS DRAWING
V1
GND
Processor
TRIMA
VMA
SMM205
COMP1
VREF_CNTL
GND
READY
START
FAULT#
V+
DC/DC
V–
Trim
On/Off
TRIM_CAPA
TRIM_CAPB
VDD_CAP
External or
Internal
VREF
Vin
FILT_CAP
UV
Vin
V+
V2
DC/DC
V–
Trim
On/Off
TRIMB
VMB
COMP2
OV
Figure 1 – Applications Schematic showing the SMM205 ADOC actively control the DC output level of 2
DC/DC Converters as well as provide margin control. The SMM205 can operate over a wide supply range
Note: This is an applications example only. Some pins, components and values are not shown.
© SUMMIT Microelectronics, Inc. 2003 • 1717 Fox Drive • San Jose CA 95131 • Phone 408 436-9890 • FAX 408 436-9897
2069 1.4 6/23/03
www.summitmicro.com
1
SMM205
Preliminary Information
Figure 2 – Example Power Supply Margining using the SMM205. The waveform on the left is margin nominal
to high from 2.5V to 2.8V and 1.8V to 2.1V. The waveform on the right is margin nominal to low from 2.5V to
2.2V and 1.8V to 1.5V. The bottom waveform is the READY signal indicating when margining is complete.
GENERAL DESCRIPTION
The SMM205 is capable of controlling and margining
the DC output voltage of LDOs or DC/DC converters
that use a trim/adjust pin and to automatically change
the level using a unique Active DC Output Control
(ADOC). The ADOC function is programmable over a
standard 2-wire I2C serial data interface and can be
used to set the nominal DC output voltage as well as
the margin high and low settings. The part actively
controls the programmed set levels to maintain tight
control over load variations and voltage drops at the
point of load. The margin range will vary depending on
the supply manufacturer and model but the normal
range is 10% adjustment around the nominal output
setting. However, the SMM205 has the capability to
margin from VREF_CNTL to VDD.
The user can set the desired voltage settings
(nominal, margin high and margin low) into the EE
memory array for the device. Then, volatile registers
are used to select one of these settings. The registers
are accessed over the I2C bus.
In normal operation, Active DC Output Control is set to
adjust the nominal output voltage of one or two
trimmed converters. Typical converters have ±2%
accuracy ratings for their output voltage. Using the
Active DC Output Control feature of the SMM205 can
increase the accuracy to ±0.2%. This high accuracy
control of a converter output voltage is extremely
important in low voltage applications where deviations
in power supply voltage can result in lower system
performance. Active DC Output Control may be
turned off by de-selecting the function in the Control
Select Register. Active DC Output Control can also be
used for margining a supply during system test.
Summit Microelectronics, Inc
When the SMM205 receives the command to margin
the Active DC Output Control will adjust the supply to
the selected margin voltage. Once the supply has
reached its margined set point the Ready bit in the
status register will set and the READY pin will go
active. If Active DC Control is disabled a margined
supply can return to its nominal voltage by writing to
the margin command register.
In order to obtain maximum accuracy the SMM205
requires an external voltage reference. An external
reference with ±0.1% accuracy will enable an overall
±0.2% accuracy for the device. A configuration option
also exists so that an internal voltage reference can be
used, but with less accuracy. Total accuracy using the
internal reference is ±0.5%. The SMM205 can be
powered from either a 12V or 8V input via an internal
regulator, or the VDD input (Figure 3).
The SMM205 has two additional input pins and one
additional output pin. The input pins, COMP1 and
COMP2, are high impedance inputs, each connected
to a comparator and compared against the
VREF_CNTL input or the internal reference (VREF).
Each comparator can be independently programmed
to monitor for UV or OV. When either of the COMP1
or COMP2 inputs are in fault the open-drain FAULT#
output will be pulled low. A configuration option exists
to disable the FAULT# output during margining.
Programming of the SMM205 is performed over the
industry standard I2C 2-wire serial data interface. A
status register is available to read the state of the part,
and a Write Protect (WP#) pin is available to prevent
writing to the configuration registers and EE memory.
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SMM205
Preliminary Information
INTERNAL BLOCK DIAGRAM
VREF_CNTL
9
MUX
COMP1 19
COMP2
12
SDA
28
SCL
1
A0
6
A1
4
A2
2
START
3
WP#
8
VDD
21
VDD_CAP 23
5
CMP
VREF
11 FAULT#
OUTPUT
CONTROL
CMP
TRIM
DRIVE A
20
TRIM
DRIVE B
16
CMP
INPUT VOLTAGE
SENSING AND
SIGNAL
CONDITIONING
I2C
INTERFACE
READY
TRIMA
18 TRIM_CAPA
TRIMB
15 TRIM_CAPB
14 VMA
17 VMB
EE
CONFIGURATION
REGISTERS
AND MEMORY
SUPPLY
ARBITRATION
10 FILT_CAP
12VIN 22
3.6V / 5V
REGULATOR
7
GND
Figure 3 –Block Diagram.
PACKAGE AND PIN CONFIGURATION
SDA
NC
NC
NC
NC
VDD_CAP
12VIN
28 Pin QFN
Top View
Pin 1
28 27 26 25 24 23 22
SCL
A2
START
A1
READY
A0
GND
1
21
2
20
3
SMM205
4
19
18
5
17
6
16
7
15
9 10 11 12 13 14
WP#
VREF_CNTL
FILT_CAP
FAULT#
COMP2
NC
VMA
8
VDD
TRIMA
COMP1
TRIM_CAPA
VMB
TRIMB
TRIM_CAPB
Summit Microelectronics, Inc
2069 1.4 6/23/03
3
SMM205
Preliminary Information
PIN DESCRIPTIONS
Pin
Number
Pin
Type
28
DATA
SDA
I2C Bi-directional data line.
1
CLK
SCL
I2C clock input.
2
I
A2
4
I
A1
6
I
A0
8
I
WP#
Write Protect active low input. When asserted writes to the configuration
registers and general purpose EE are not allowed.
10
CAP
FILT_CAP
External capacitor input used to filter the VM inputs.
15, 18
CAP
TRIM_CAPx
External capacitor input used for Active Control and margining.
16, 20
O
TRIMx
Output voltage used to control and/or margin converter voltages. Connect
to the converter trim input.
14, 17
I
VMx
Voltage monitor input. Connect to the DC/DC converter positive sense line
or its +Vout pin.
9
I
VREF_CNTL
Voltage reference input used for DC output control and margining.
VREF_CNTL can be programmed to output the internal 1.25V reference
voltage. Pin should be left open if using VREF internal.
21
PWR
VDD
Power supply of the part.
7
GND
GND
Ground of the part. The SMM205 ground pin should be connected to the
ground of the device under control or to a star point ground. PCB layout
should take into consideration ground drops.
22
PWR
12VIN
12V power supply input internally regulated to either 3.6V or 5.5V. When
using the 3.6V internal regulator option the voltage input can be as low as
8V. It can be as high as 15V using the 5.5V internal regulator.
3
I
START
Programmable active high/low input. The START input is used solely for
enabling Active Control and/or margining.
READY
Programmable active high/low open drain output indicates that VM is at its
set point. When programmed as an active high output READY can also be
used as an input. When pulled low it will latch the state of the comparator
inputs.
VDD_CAP
External capacitor input used to filter the internal supply rail.
COMP1 and COMP2 are high impedance inputs, each connected internally
to a comparator and compared against the VREF_CNTL input. Each
comparator can be independently programmed to monitor for UV or OV.
The monitor level is set externally with a resistive voltage divider.
Pin Name
5
I/O
23
CAP
19
I
COMP1
12
I
COMP2
11
O
13, 24-27
NC
Summit Microelectronics, Inc
Pin Description
The address pins are biased either to VDD_CAP or GND. When
communicating with the SMM205 over the 2-wire bus these pins provide a
mechanism for assigning a unique bus address.
FAULT#
When either of the COMP1 or COMP2 inputs are in fault the open-drain
FAULT# output will be pulled low. A configuration option exists to disable
the FAULT# output while the device is margining.
NC
No Connect. Leave floating; do not connect anything to the NC pins.
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SMM205
Preliminary Information
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED OPERATING CONDITIONS
Temperature Under Bias ......................–55°C to 125°C
Storage Temperature............................–65°C to 150°C
Terminal Voltage with Respect to GND:
VDD Supply Voltage .........................–0.3V to 6.0V
12VIN Supply Voltage.....................–0.3V to 15.0V
All Others ............................... –0.3V to VDD + 0.7V
Output Short Circuit Current ............................... 100mA
Lead Solder Temperature (10 secs)……………….300°C
Junction Temperature.........................…….....…...150°C
ESD Rating per JEDEC……………………..……..2000V
Latch-Up testing per JEDEC………..……......…±100mA
Temperature Range (Industrial) .......... –40°C to +85°C
(Commercial)............ –5°C to +70°C
VDD Supply Voltage.................................. 2.7V to 5.5V
12VIN Supply Voltage (1)........................ 8.0V to 14.0V
VIN.............................................................GND to VDD
VOUT.......................................................GND to 15.0V
Package Thermal Resistance (θJA)
28 Lead QFN………………………………….…80oC/W
Note - The device is not guaranteed to function outside its operating
rating. Stresses listed under Absolute Maximum Ratings may cause
permanent damage to the device. These are stress ratings only and
functional operation of the device at these or any other conditions
outside those listed in the operational sections of the specification is
not implied. Exposure to any absolute maximum rating for extended
periods may affect device performance and reliability. Devices are
ESD sensitive. Handling precautions are recommended.
Moisture Classification Level 1 (MSL 1) per J-STD- 020
Note (1) — Range depends on internal regulator set to 3.6V or 5.5V,
see 12VIN specification below.
DC OPERATING CHARACTERISTICS
(Over recommended operating conditions, unless otherwise noted. All voltages are relative to GND.)
Symbol
Parameter
Notes
Min.
Typ.
Max
Unit
VDD
Supply Voltage
12VIN
Supply Voltage
VM
Positive Sense Voltage
VADOC
Power Supply Current from
VDD
Power Supply Current from
12VIN
TRIM output current
through 100Ω to 1.0V
Margin Control/ADOC
Range
VIH
Input High Voltage
VIL
Input Low Voltage
IDD
I12VIN
ITRIM
OV/UV
Programmable Open Drain
Output (READY)
Monitor Voltage Range
VHYST
Base DC Hysteresis
VOL
2.7
3.3
5.5
V
V
Internally regulated to 5.5V
10
15
Internally regulated to 3.6V
6
14
–0.3
VDD
V
VM pin
All TRIM pins and 12VIN floating
3
5
mA
All TRIM pins and VDD floating
3
5
mA
TRIM Sourcing Max Current
TRIM Sinking Max Current
Depends on Trim range of DCDC Converter
VDD = 2.7V
VDD = 5.0V
VDD = 2.7V
VDD = 5.0V
1.5
1.5
VREF_CNTL
VDD
0.9xVDD
0.7xVDD
VDD
VDD
0.1xVDD
0.3xVDD
ISINK = TBD
COMP1 and COMP2 pins
COMP1 and COMP2 pins,
VTH – VTL — Note 1
mA
mA
0.2
–0.3
3
V
V
V
VDD
10
V
V
mV
Note 1 – The Base DC Hysteresis voltage is measured with a 1.25V external voltage source. The resulting value is determined by subtracting
Threshold Low from Threshold High (VTH – VTL) while monitoring the FAULT# pin state. Base DC Hysteresis is measured with a 1.25V input. Actual
DC Hysteresis is derived from the equation: (VIN/VREF)(Base Hysteresis). For example, if VIN = 2.5V and VREF = 1.25V then Actual DC Hysteresis =
(2.5V/1.25V) (0.003V) = 6mV.
Summit Microelectronics, Inc
2069 1.4 6/23/03
5
SMM205
Preliminary Information
DC OPERATING CHARACTERISTICS (CONTINUED)
(Over recommended operating conditions, unless otherwise noted. All voltages are relative to GND.)
Symbol
Parameter
Notes
Min.
Typ.
Max
Unit
1.25VREF Output
VREF
1.24
1.25
1.26
V
RLOAD = 2KΩ to GND
Voltage
External VREF Voltage
0.25
VDD
V
VREF_CNTL
Range
ADOCACC
External VREF=1.25V, ±0.1%
-0.2
+0.2
%
ADOC trimmed to internal VREF
-0.5
+0.5
%
ADOC/Margin Accuracy
AC OPERATING CHARACTERISTICS
(Over recommended operating conditions, unless otherwise noted. All voltages are relative to GND.)
Symbol
Parameter
Notes
Min.
Typ.
Max
Unit
tDC_CONTROl
Tsettling
TTRIM
Active DC Control
sampling period
Update period for Active DC
Control
1.7
ms
Settling Time
+ 10% change in voltage with
0.1% ripple
100
ms
Fast Margin, nom to high,
TRIM_CAP=1µF
20
ms
Slow Margin, nom to high,
TRIM_CAP=1µF
200
ms
Trim Speed
Summit Microelectronics, Inc
2069 1.4 6/23/03
6
SMM205
Preliminary Information
I2C 2-WIRE SERIAL INTERFACE AC OPERATING CHARACTERISTICS – 100/400kHz
Over recommended operating conditions, unless otherwise noted. All voltages are relative to GND. See Figure 4 Timing Diagram.
Conditions
Symbol
Description
fSCL
SCL Clock Frequency
tLOW
Clock Low Period
tHIGH
Clock High Period
100kHz
Min
Typ
0
Before New Transmission
- Note 1/
400kHz
Max
Min
100
0
Typ
Max
Units
400
KHz
4.7
1.3
µs
4.0
0.6
µs
4.7
1.3
µs
tBUF
Bus Free Time
tSU:STA
Start Condition Setup Time
4.7
0.6
µs
tHD:STA
Start Condition Hold Time
4.0
0.6
µs
tSU:STO
Stop Condition Setup Time
4.7
0.6
µs
tAA
Clock Edge to Data Valid
SCL low to valid
SDA (cycle n)
tDH
Data Output Hold Time
SCL low (cycle n+1)
to SDA change
tR
SCL and SDA Rise Time
Note 1/
1000
1000
ns
tF
SCL and SDA Fall Time
Note 1/
300
300
ns
tSU:DAT
Data In Setup Time
250
150
ns
tHD:DAT
Data In Hold Time
0
0
ns
TI
Noise Filter SCL and SDA
tWR
Write Cycle Time
0.2
0.2
Noise suppression
3.5
0.2
0.9
0.2
100
µs
µs
100
5
ns
5
ms
Note: 1/ - Guaranteed by Design.
TIMING DIAGRAMS
tR
tF
tSU:SDA
t HD:SDA
t W R (For W rite O peration Only)
tHIGH
t LOW
SCL
SDA
tSU:DAT
tSU:STO
tBUF
(IN)
tAA
SDA
tHD:DAT
t DH
(OUT)
Figure 4 . Basic I2C Serial Interface Timing
Summit Microelectronics, Inc
2069 1.4 6/23/03
7
SMM205
Preliminary Information
APPLICATIONS INFORMATION
DEVICE OPERATION
POWER SUPPLY
The SMM205 can be powered by either an 8V to 15V
input through the 12VIN pin or by a 2.7V to 5.5V input
through the VDD pin. The 12VIN pin feeds an internal
programmable regulator that internally generates
either 5.5V or 3.6V. The internal regulator must be set
to 3.6V if using an 8V supply. A voltage arbitration
circuit allows the device to be powered by the highest
voltage from either the regulator output or the VDD
input. This voltage arbitration circuit continuously
checks for these voltages to determine which will
power the SMM205. The resultant internal power
supply rail is connected to the VDD_CAP pin that
allows both filtering and hold-up of the internal power
supply.
VOLTAGE REFERENCE
The SMM205 can operate using either an internal or
external voltage reference, VREF. The internal VREF
is set to 1.25V. Total accuracy with a ±0.1% external
reference is ±0.2%, and ±0.5% using the internal
reference.
MODES OF OPERATION
The SMM205 has one key feature: Active DC Output
Control (ADOC), and two basic modes of operation:
UV/OV monitoring mode and supply margining mode.
A detailed description of each feature and mode
follows.
ACTIVE DC OUTPUT CONTROL (ADOC)
The SMM205 can control the DC output voltage of
bricks or DC/DC converters that have a trim pin. The
TRIM pin on the SMM205 is connected to the trim
input pin on the power supply converter. A sense line
from the channel’s point-of-load connects to the VM
input. The Active DC Control function cycles every
1.7ms making slight adjustments to the voltage on the
TRIM output pin based on the voltage input on the VM
pin. This voltage adjustment allows the SMM205 to
control the output voltage of the power supply
converter to within ±0.2% when using a ±0.1%
external voltage reference.
Summit Microelectronics, Inc
The voltage on the TRIM_CAP pins is buffered and
applied to the TRIM pin. The voltage adjustments on
the TRIM pin cause a slight ripple of less than 1mV on
the power supply voltage. The amplitude of this ripple
is a function of the TRIM_CAP capacitor and the trim
gain of the converter. Calculation of the TRIM_CAP
capacitor to achieve a desired minimum ripple is
detailed in Application Note 37.
The device can be programmed to either enable or
disable the Active DC Control function.
When
disabled or not active the TRIM pin on the SMM205 is
a high impedance input. The voltage on the TRIM pin
is buffered and applied to the TRIM_CAP pin charging
the capacitor. This allows a smooth transition from the
converter’s nominal voltage to the SMM205 controlling
that voltage to the Active DC Control nominal setting.
There is a programmable Speed-Up Convergence
option. As the name implies, this option decreases the
time required to bring a supply voltage from the
converter’s nominal output voltage to the Active DC
Output Control nominal voltage setting.
MONITORING
The SMM205 monitors the COMP1 and COMP2
inputs as well as the VM pins. COMP1 and COMP2
are high impedance inputs, each connected internally
to a comparator and compared against the
VREF_CNTL input.
Each comparator can be
independently programmed to monitor for either UV or
OV. The monitor level is set externally with a resistive
voltage divider. The part can be programmed to
trigger the FAULT# pin when either COMPx
comparator has exceeded the UV or OV range. The
READY and FAULT# outputs of the SMM205 are
active as long as the triggering limit remains in a fault
condition. The READY pin is programmable active
high/low open drain output indicates that VM is at its
set point. When programmed as an active high output
READY can also be used as an input. When pulled
low it will latch the state of the comparator inputs.
When either of the COMP1 or COMP2 inputs are in
fault the open-drain FAULT# output will be pulled low.
A configuration option exists to disable the FAULT#
output while the device is in margining mode.
2069 1.4 6/23/03
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SMM205
Preliminary Information
APPLICATIONS INFORMATION (CONTINUED)
STATUS REGISTER
A status register exists for I2C polling of the status of
the COMP1 and COMP2 inputs. Two bits in this
status register reflect the current state of the inputs (1
= fault, 0 = no fault). Two additional bits show the
state of the inputs latched by one of two events
programmed in the configuration. The first event
option is the FAULT# output going active. The second
event option is the READY pin going low. The READY
pin is an I/O. As an output the READY output pin
goes active when the DC controlled voltages are at
their set point. As an input programmed to active high
it can be pulled low externally and latch the state of
the COMP inputs. This second event option allows
the state of the COMP inputs on multiple devices to be
latched at the same time while a host monitors their
FAULT# outputs.
MARGINING
The SMM205 has two additional Active DC Output
Control voltage settings: margin high and margin low.
The margin high and margin low settings can be as
much as ±10% of the nominal setting depending on
the manufacturer. The SMM205 range can be as
large as VREF_CNTL to VDD. These settings are
stored in the configuration registers and are loaded
into the Active DC Output Control voltage setting by
margin commands issued via the I2C bus. The device
must be enabled for Active DC Output Control in order
to enable margining.
The margin command registers contain two bits that
decode the commands to margin high, to margin low,
or to control to the nominal setting. Once the SMM205
receives the command to margin the supply voltage it
begins adjusting the supply voltage to move toward
the desired setting. When this voltage setting is
reached a bit is set in the margin status registers and
the READY signal becomes active.
Note: Configuration writes or reads of registers 00HEX
to 03HEX should not be performed while the SMM205 is
margining.
WRITE PROTECTION
Write protection for the SMM205 is located in a volatile
register where the power-on state is defaulted to write
protect. There are separate write protect modes for
the configuration registers and memory. In order to
remove write protection the code 55HEX is written to the
write protection register. Other codes will also enable
write protection. For example, writing 59HEX will allow
writes to the configuration register but not to the
memory, while writing 35HEX will allow writes to the
memory but not to the configuration registers. The
SMM205 also features a Write Protect pin (WP#)
which, when asserted, prevents writing to the
configuration registers and EE memory. In addition to
these two forms of write protection there is also a
configuration register lock bit which, once
programmed, does not allow the configuration
registers to be changed.
Figure 5 – SMM205 margin example. The nominal setting for channel 1 and 2 is 2.5V and 1.8V. The device
margins the DC/DC converters from nominal to high (2.8V and 2.1) then to nominal, then to low (2.3V and
1.5V), then to nominal, then to channel 1 high and channel 2 low, and then back to nominal. The READY
signals goes low when margining and high when complete.
Summit Microelectronics, Inc
2069 1.4 6/23/03
9
SMM205
Preliminary Information
APPLICATIONS INFORMATION (CONTINUED)
Figure 6 – SMM205 Applications schematic. The accuracy of the external (U4) or internal reference sets the
accuracy of the ADOC function. Total accuracy with a ±0.1% external reference is ±0.2% and ±0.5% with the
internal reference. The 12V supply can go as low as 8V if the internal regulator is set to 3.6V.
Summit Microelectronics, Inc
2069 1.4 6/23/03
10
SMM205
Preliminary Information
APPLICATIONS INFORMATION (CONTINUED)
+12VIN (+10V to +15V)
C7
0.1uF
0.01uF
C8
0.1uF
R6 10K
R7 10K
1
28
6
4
2
R1 10K
8
D1
SCL
SDA
A0
A1
A2
VMB
TRIMB
TRIM_CAPB
SMM205
WP#
13
24
25
26
27
DIODE
J1
1
3
5
7
9
Gnd
SCL
Gnd3
SDA
Rsrv5
MR
+10V Rsrv8
+5V Rsrv10
FILT_CAP
COMP1
COMP2
GND
R2 10K
TRIM_CAPA
TRIMA
VMA
18
20
14
R3
RTRIM
VOUT
U2
17
16
15
Switching Regulator
+Vin
R4
RSET1
+Vout
10
19
12
PGOOD
C5
0.02uF
VADJ (VREF)
R5
20k
START
7
FAULT#
START
READY
FAULT#
NC
NC
NC
NC
NC
3
5
11
READY
C1 1uF
21
23
22
9
U3
Vdd
VddCap
12VIn
VRef Cntl
R8 10K
START
For Example:
If Vout=3.3V, R4=63.4K, 15% of Vout=0.5V
ITRIM=8uA, RTRIM=62.5K
Therefore Rtrim standard 1% value down
from 62.5K
Gnd
C4
RTRIM(R3) is calculated as follows:
VTRIMlow=0.3V, Regulator VREF=0.8V
The current through R3 is ITRIM=(0.8-0.3)/RTRIM
(ITRIM)(R4) > 15% of VOUT
RTRIMmax should be < the calculated value
2
4
6
8
10
SMX3200 I2C Programming
Connector 10 pin Header
R1 and R2 need only be
placed once on the I2C bus
The SMM205 START pin must be inactive during power-up so
that the TRIM pin is high impedence. Once power is nominal,
the START pin can be active to start margin and ADOC
functions
Figure 7 – SMM205 Applications schematic for an adjustable switching regulator (Full regulator circuit not
shown).
Summit Microelectronics, Inc
2069 1.4 6/23/03
11
SMM205
Preliminary Information
DEVELOPMENT HARDWARE & SOFTWARE
The Windows GUI software will generate the data and
send it in I2C serial bus format so that it can be directly
downloaded to the SMM205 via the programming
Dongle and cable. An example of the connection
interface is shown in Figure 8.
The end user can obtain the Summit SMX3200
programming
system
for
device
prototype
development. The SMX3200 system consists of a
programming Dongle, cable and WindowsTM GUI
software. It can be ordered on the website or from a
local representative.
The latest revisions of all
software and an application brief describing the
SMX3200
is
available
from
the
website
(www.summitmicro.com).
When design prototyping is complete, the software
can generate a HEX data file that should be
transmitted to Summit for approval. Summit will then
assign a unique customer ID to the HEX code and
program production devices before the final electrical
test operations.
This will ensure proper device
operation in the end application.
The SMX3200 programming Dongle/cable interfaces
directly between a PC’s parallel port and the target
application. The device is then configured on-screen
via an intuitive graphical user interface employing
drop-down menus.
T op view of straight 0.1" x 0.1 closed-side
connector. SMX3200 interface cable connector.
D1
Positive
Supply
Pin 10, Reserved
Pin 8, Reserved
Pin 6, MR#
Pin 4, SDA
Pin 2, SCL
1N4148
VDD_CAP
SMM205
W P#
SDA
SCL
10
8
6
4
2
9
7
5
3
1
Pin 9, 5V
Pin 7, 10V
Pin 5, Reserved
Pin 3, G ND
Pin 1, G ND
C1
0.1 F
G ND
Common
G round
Figure 8– SMX3200 Programmer I2C serial bus connections to program the SMM205. The SMM205 has a
Write Protect pin (WP#) which, when asserted, prevents writing to the configuration registers and EE
memory. In addition, there is a configuration register lock bit which, once programmed, does not allow the
configuration registers to be changed.
Summit Microelectronics, Inc
2069 1.4 6/23/03
12
SMM205
Preliminary Information
I2C PROGRAMMING INFORMATION
SERIAL INTERFACE
Access to the configuration registers, general-purpose
memory and command and status registers is carried
out over an industry standard 2-wire serial interface
(I2C). SDA is a bi-directional data line and SCL is a
clock input. Data is clocked in on the rising edge of
SCL and clocked out on the falling edge of SCL. All
data transfers begin with the MSB. During data
transfers SDA must remain stable while SCL is high.
Data is transferred in 8-bit packets with an intervening
clock period in which an Acknowledge is provided by
the device receiving data. The SCL high period (tHIGH)
is used for generating Start and Stop conditions that
precede and end most transactions on the serial bus.
A high-to-low transition of SDA while SCL is high is
considered a Start condition, while a low-to-high
transition of SDA while SCL is high is considered a
Stop condition.
The interface protocol allows operation of multiple
devices and types of devices on a single bus through
unique device addressing.
The address byte is
comprised of a 4-bit device type identifier (slave
address) and a 3-bit bus address. The remaining bit
indicates either a read or a write operation. Refer to
Table 1 for a description of the address bytes used by
the SMM205.
The device type identifier for the memory array, the
configuration registers and the command and status
registers are accessible with the same slave address.
It can be programmed to any four bit number 0000BIN
through 1111BIN.
The bus address bits, A2, A1 and A0, are hard wired
though pins 2, 4 and 6 (A2, A1 and A0). The bus
address accessed in the address byte of the serial
data stream must match the setting on the SMM205
address pins.
Summit Microelectronics, Inc
WRITE
Writing to the memory or a configuration register is
illustrated in Figures 9, 10, 11, 13, 14 and 16. A Start
condition followed by the address byte is provided by
the host; the SMM205 responds with an Acknowledge;
the host then responds by sending the memory
address pointer or configuration register address
pointer; the SMM205 responds with an acknowledge;
the host then clocks in one byte of data. For memory
and configuration register writes, up to 15 additional
bytes of data can be clocked in by the host to write to
consecutive addresses within the same page. After
the last byte is clocked in and the host receives an
Acknowledge, a Stop condition must be issued to
initiate the nonvolatile write operation.
READ
The address pointer for the configuration registers,
memory, command and status registers and ADC
registers must be set before data can be read from the
SMM205. This is accomplished by issuing a dummy
write command, which is simply a write command that
is not followed by a Stop condition. The dummy write
command sets the address from which data is read.
After the dummy write command is issued, a Start
command followed by the address byte is sent from
the host. The host then waits for an Acknowledge and
then begins clocking data out of the slave device. The
first byte read is data from the address pointer set
during the dummy write command. Additional bytes
can be clocked out of consecutive addresses with the
host providing an Acknowledge after each byte. After
the data is read from the desired registers, the read
operation is terminated by the host holding SDA high
during the Acknowledge clock cycle and then issuing a
Stop condition. Refer to Figures 12, 15 and 17 for an
illustration of the read sequence.
WRITE PROTECTION
The SMM205 powers up into a write protected mode.
Writing a code to the volatile write protection register
(write only) can disable the write protection. The write
protection register is located at address 42HEX. Writing
to the write protection register is shown in Figure 9.
Writing 0101BIN to bits [7:4] of the write protection
register allows writes to the general-purpose memory
while writing 0101BIN to bits [3:0] allows writes to the
configuration registers. The write protection can be reenabled by writing other codes (not 0101BIN) to the
write protection register.
2069 1.4 6/23/03
13
SMM205
Preliminary Information
I2C PROGRAMMING INFORMATION (CONTINUED)
CONFIGURATION REGISTERS
The majority of the configuration registers are grouped
with the general-purpose memory. Writing and reading
the configuration registers is shown in Figures 10, 11
and 12.
Note: Configuration writes or reads of registers 00HEX
to 03HEX should not be performed while the SMM205
is margining.
GENERAL-PURPOSE MEMORY
The 1k-bit general-purpose memory is located at any
slave address. The bus address bits are hard wired
by the address pins A2, A1 and A0. Memory writes
and reads are shown in Figures 13, 14 and 15.
Slave Address
ANY
Bus Address
A2 A1 A0
COMMAND AND STATUS REGISTERS
Writes and reads of the command and status registers
are shown in Figures 16 and 17.
GRAPHICAL USER INTERFACE (GUI)
Device configuration utilizing the Windows based
SMM205 graphical user interface (GUI) is highly
recommended. The software is available from the
Summit website (www.summitmicro.com). Using the
GUI in conjunction with this datasheet and Application
Note 38 simplifies the process of device prototyping
and the interaction of the various functional blocks. A
programming Dongle (SMX3200) is available from
Summit to communicate with the SMM205. The
Dongle connects directly to the parallel port of a PC
and programs the device through a cable using the I2C
bus protocol. See figure 8 and the SMX3200 Data
Sheet.
Register Type
Configuration Registers are located in
00 HEX thru 45HEX
General-Purpose Memory is located in
80 HEX thru FFHEX
Table 1 - Address bytes used by the SMM205.
Summit Microelectronics, Inc
2069 1.4 6/23/03
14
SMM205
Preliminary Information
I2C PROGRAMMING INFORMATION (CONTINUED)
Master
S
T
A
R
T
Configuration
Register Address = 42HEX
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
A
0
W
0
1
A
C
K
Slave
0
0
0
0
4HEX
S
T
O
P
Data = 55HEX
1
0
0
1
0
1
0
1
0
1
A
C
K
2HEX
A
C
K
Write Protection
Register Address
5HEX Unlocks
General Purpose
EE
5HEX Unlocks
Configuration
Registers
Figure 9 – Write Protection Register Write
M aster
S
T
A
R
T
Configuration
Register Address
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
A
0
C
6
C
7
W
C
5
C
4
C
3
Data
C
2
C
1
C
0
D
7
A
C
K
Slave
S
T
O
P
D
6
D
5
D
4
D
3
D
2
D
1
D
0
A
C
K
A
C
K
Figure 10 – Configuration Register Byte Write
M aster
S
T
A
R
T
Configuration
Register Address
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
A
0
C
6
C
5
C
4
C
3
C
2
C
1
C
0
A
C
K
Slave
D
7
D
6
D
7
D
6
D
5
D
4
D
3
D
5
D
4
D
3
D
2
D
1
D
0
A
C
K
A
C
K
S
T
O
P
Data (16)
Data (2)
M aster
Slave
C
7
W
Data (1)
D
2
D
1
D
0
D
7
D
6
D
5
D
2
A
C
K
D
1
D
0
D
7
D
6
D
5
D
4
A
C
K
D
3
D
2
D
1
D
0
A
C
K
Figure 11 – Configuration Register Page Write
Summit Microelectronics, Inc
2069 1.4 6/23/03
15
SMM205
Preliminary Information
I2C PROGRAMMING INFORMATION (CONTINUED)
M aster
S
T
A
R
T
Configuration
Register Address
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
S
T
A
R
T
A
0
C
7
W
C
6
C
5
C
4
C
3
C
2
C
1
S
A
3
C
0
A
C
K
Slave
D
7
D
6
D
5
D
4
D
3
D
2
D
1
S
A
2
S
A
0
A
2
A
1
A
0
R
A
C
K
A
C
K
D
0
S
A
1
A
C
K
A
C
K
Data (1)
M aster
Bus Address
D
7
D
6
D
5
D
2
D
1
N
A
C
K
Data (n)
D
0
D
7
D
6
D
5
D
4
D
3
D
2
D
1
S
T
O
P
D
0
Slave
Figure 12 - Configuration Register Read
M aster
S
T
A
R
T
Configuration
Register Address
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
A
0
C
6
C
7
W
C
5
C
4
C
3
Data
C
2
C
1
C
0
D
7
A
C
K
Slave
S
T
O
P
D
6
D
5
D
4
D
3
D
2
D
1
D
0
A
C
K
A
C
K
Figure 13 – General Purpose Memory Byte Write
M aster
S
T
A
R
T
Configuration
Register Address
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
A
0
C
6
C
5
C
4
C
3
C
2
C
1
C
0
A
C
K
Slave
D
7
D
6
D
7
D
6
D
5
D
4
D
3
D
5
D
4
D
3
D
2
D
1
D
0
A
C
K
A
C
K
Data (2)
M aster
Slave
C
7
W
Data (1)
S
T
O
P
Data (16)
D
2
D
1
D
0
D
7
D
6
D
5
D
2
A
C
K
D
1
D
0
D
7
D
6
D
5
D
4
A
C
K
D
3
D
2
D
1
D
0
A
C
K
Figure 14 - General Purpose Memory Page Write
Summit Microelectronics, Inc
2069 1.4 6/23/03
16
SMM205
Preliminary Information
I2C PROGRAMMING INFORMATION (CONTINUED)
M aster
S
T
A
R
T
Configuration
Register Address
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
A
0
S
T
A
R
T
C
7
W
C
6
C
5
C
4
C
3
C
2
C
1
M aster
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
S
A
1
S
A
0
A
2
A
1
A
0
R
A
C
K
A
C
K
D
7
S
A
2
A
C
K
A
C
K
Data (1)
S
A
3
C
0
A
C
K
Slave
Bus Address
D
6
D
5
D
2
D
1
D
0
N
A
C
K
Data (n)
D
7
D
6
D
5
D
4
D
3
D
2
D
1
S
T
O
P
D
0
Slave
Figure 15 - General Purpose Memory Read
M aster
S
T
A
R
T
Command and Status
Register Address
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
A
0
C
7
W
C
6
C
5
C
4
C
3
C
2
Data
C
1
C
0
A
C
K
Slave
S
T
O
P
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
A
C
K
A
C
K
Figure 16 – Command and Status Register Write
M aster
S
T
A
R
T
Command and Status
Register Address
Bus Address
S
A
3
S
A
2
S
A
1
S
A
0
A
2
A
1
A
0
S
T
A
R
T
C
7
W
C
6
C
5
C
4
C
3
C
2
C
1
C
0
A
C
K
Slave
M aster
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
S
A
1
S
A
0
A
2
A
1
A
0
R
A
C
K
A
C
K
D
7
S
A
2
A
C
K
A
C
K
Data (1)
Bus Address
S
A
3
D
6
D
5
D
2
D
1
D
0
N
A
C
K
Data (n)
D
7
D
6
D
5
D
4
D
3
D
2
D
1
S
T
O
P
D
0
Slave
Figure 17 - Command and Status Register Read
Summit Microelectronics, Inc
2069 1.4 6/23/03
17
SMM205
Preliminary Information
DEFAULT CONFIGURATION REGISTER SETTINGS – SMM205F-167
Register
R00
R01
Contents
01
FF
Function
Channel A Nominal Voltage is set to 2.503V (MSB)
Channel A Nominal Voltage is set to 2.503V (MSB)
R02
02
Channel B Nominal Voltage is set to 1.801V (MSB)
R03
C6
Channel B Nominal Voltage is set to 1.801V (MSB)
R04
AF
Channel A and B ADOC is enabled, Trim polarity is inverse, Fast Convergence,
VREF External, Fault Latched by a Fault Condition
R05
05
R06
28
R08
R0C
R0D
R20
R21
R22
R23
R30
R31
R32
R33
R40
R41
R42
R44
00
12
50
01
C8
02
61
02
45
03
54
00
03
FF
00
Slave address is 0101
No Write Command Required to Activate ADOC, Internal Regulator set to 3.6V,
Fault Output Enabled While Margining, Configuration Registers Unlocked, COMP1
and COMP2 are set to sense UV
Margin Command Bits
Stores VREF_CNTL value set to 1.25
Stores VREF_CNTL value set to 1.25
Channel A - Margin High Voltage is set to 2.805V (MSB)
Channel A - Margin High Voltage is set to 2.805V (LSB)
Channel B - Margin High Voltage is set to 2.100V (MSB)
Channel B - Margin High Voltage is set to 2.100V (LSB)
Channel A - Margin Low Voltage is set to 2.201V (MSB)
Channel A - Margin Low Voltage is set to 2.201V (LSB)
Channel B - Margin Low Voltage is set to 1.501V (MSB)
Channel B - Margin Low Voltage is set to 1.501V (LSB)
Margin Command Status Bits
READY and START pin Polarities set to Active High
Write Protect
Fault Status Bits
RC1
The default device ordering number — SMM205F-167 — is programmed as described
above and tested over the commercial temperature range. Application Note 41 contains a
complete description of the Windows GUI and the default settings of each of the 22
individual Configuration Registers.
Summit Microelectronics, Inc
2069 1.4 6/23/03
18
SMM205
Preliminary Information
PACKAGE
28 Pin QFN
Summit Microelectronics, Inc
2069 1.4 6/23/03
19
SMM205
Preliminary Information
PART MARKING
Sum mit Part Number
SUM M IT
SM M 205N
Annn
Status Tracking Code
(Blank, MS, ES, 01, 02,...)
(Sum m it Use)
xx
AYYW W
Pin 1
Date Code (YYW W )
Lot tracking code (Sum m it use)
Part Number suffix
(Contains Customer specific ordering requirements)
Product T racking Code (Summit use)
Drawing not to scale
ORDERING INFORMATION
SMM205
Summit Part Number
N
nnn
Part Number Suffix (see page 18)
Package
N=28 Lead QFN
Specific requirements are contained in the suffix
such as Commercial or Industrial Temp Range,
Hex code, Hex code revision, etc.
NOTICE
NOTE 1 - This is a Preliminary Information data sheet that describes a Summit product currently in pre-production with limited characterization.
SUMMIT Microelectronics, Inc. reserves the right to make changes to the products contained in this publication in order to improve design,
performance or reliability. SUMMIT Microelectronics, Inc. assumes no responsibility for the use of any circuits described herein, conveys no
license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules
contained herein reflect representative operating parameters, and may vary depending upon a user’s specific application. While the information in
this publication has been carefully checked SUMMIT Microelectronics, Inc. shall not be liable for any damages arising as a result of any error or
omission.
SUMMIT Microelectronics, Inc. does not recommend the use of any of its products in life support or aviation applications where the failure or
malfunction of the product can reasonably be expected to cause any failure of either system or to significantly affect their safety or effectiveness.
Products are not authorized for use in such applications unless SUMMIT Microelectronics, Inc. receives written assurances, to its satisfaction, that:
(a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; and (c) potential liability of SUMMIT Microelectronics, Inc.
is adequately protected under the circumstances.
Revision 1.4 — This document supersedes all previous versions. Please check the Summit Microelectronics, Inc. web site for data sheet updates
www.summitmicro.com.
© Copyright 2003 SUMMIT MICROELECTRONICS, Inc.
Power Management for Communications™
I2C is a trademark of Philips Corporation.
Summit Microelectronics, Inc
2069 1.4 6/23/03
20