A low-drift, on-chip reference and 14-bit ΔΣ A/D converter
allow precise measurements of supply voltages, load
currents or internal die temperature. Fault management
allows
ALERT
to be asserted for configurable overvoltage
and undervoltage fault conditions. Two voltage buffered,
8-bit IDACs allow highly accurate programming of DC/DC
converter output voltages. The IDACs can be configured
to automatically servo the power supplies to the desired
voltages using the ADC. The LTC2970-1 adds a tracking
feature that can be used to turn multiple power supplies
on or off in a controlled manner.
The bus address is set to 1 of 9 possible combinations by
pin strapping the ASEL0 and ASEL1 pins. The LTC2970/
LTC2970-1 are packaged in a 24-pin, 4mm
×
5mm QFN
package.
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
n
n
n
n
Less Than ±0.5% Total Unadjusted Error 14-Bit
DΣ
ADC with On-Chip Reference
Dual, 8-Bit IDACs with 1x Voltage Buffers
Linear, Voltage Servo Adjusts Supply Voltages by
Ramping IDAC Outputs Up/Down
I
2
C Bus Interface (SMBus Compatible)
Extensive, User Configurable Fault Monitoring
On-Chip Temperature Sensor
Available in 24-Pin 4mm
×
5mm QFN Package
applicaTions
n
n
n
n
Dual Power Supply Voltage Servo
Monitoring Supply Voltage and Current
Programmable Power Supplies
Programmable Reference
Typical applicaTion
Dual Power Supply Monitor and Controller (One of Two Channels Shown)
8V TO 15V
0.50
12V
IN
V
IN
IN
OUT
1/2 LTC2970
GPIO_CFG
I+
I–
DC/DC
CONVERTER
V
IN0_BP
V
IN0_BM
V
OUT0
V
IN0_AP
RUN/SS
GND
FB
LOAD
I
OUT0
V
IN0_AM
ALERT
SCL
SDA
GPIO_0
REF
0.1µF
I
2
C BUS
SMBUS
COMPATIBLE
V
DD
0.1µF
ERROR (%)
0
0.1µF
0.25
16 PARTS MOUNTED ON PCB
ADC Total Unadjusted Error
vs Temperature
(
)
–0.25
ADC VIN = 5V
–0.50
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
29701 TA01b
SGND
GND ASEL0 ASEL1
29701 TA01
29701fe
For more information
www.linear.com/LTC2970
1
LTC2970/LTC2970-1
absoluTe MaxiMuM raTings
(Notes 1 and 2)
pin conFiguraTion
TOP VIEW
GPIO_CFG
19 SDA
18 SCL
25
GND
17
ALERT
16 GPIO_0
15 GPIO_1
14 I
OUT0
13 I
OUT1
V
OUT1
ASEL0
12V
IN
ASEL1
V
OUT0
RGND
V
IN0_AP
V
IN0_AM
V
IN0_BP
V
IN0_BM
V
IN1_AP
V
IN1_AM
V
IN1_BP
1
2
3
4
5
6
7
8
V
IN1_BM
9 10 11 12
V
DD
REF
Supply Voltages:
V
DD
.......................................................... –0.3V to 6V
12V
IN
..................................................... –0.3V to 15V
Digital Input/Output Voltages:
ASEL0, ASEL1 ............................. –0.3V to V
DD
+ 0.3V
SDA, SCL, GPIO_CFG,
ALERT,
GPIO_0, GPIO_1........................... –0.3V to 6V
Analog Voltages:
V
IN0_AP
, V
IN0_AM
, V
IN0_BP
,
V
IN0_BM
, V
IN1_AP
, V
IN1_AM
,
V
IN1_BP
, V
IN1_BM
, V
OUT0
, V
OUT1
............... –0.3V to 6V
I
OUT0
, I
OUT1
, REF ......................... –0.3V to V
DD
+ 0.3V
RGND.................................................... –0.3V to 0.3V
Operating Ambient Temperature Range:
LTC2970C ................................................ 0°C to 70°C
LTC2970I .............................................–40°C to 85°C
LTC2970H .......................................... –40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
24 23 22 21 20
UFD PACKAGE
24-LEAD (4mm
×
5mm) PLASTIC QFN
T
JMAX
= 150°C,
θ
JA
= 34°C/W,
θ
JC
= 3°C/W
EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH
LTC2970CUFD#PBF
LTC2970CUFD-1#PBF
LTC2970IUFD#PBF
LTC2970IUFD-1#PBF
LTC2970HUFD#PBF
LTC2970HUFD-1#PBF
TAPE AND REEL
LTC2970CUFD#TRPBF
http://www.linear.com/product/LTC2970#orderinfo
PART MARKING*
2970
29701
2970
29701
2970
29701
PACKAGE DESCRIPTION
24-Pin (4mm
×
5mm) Plastic QFN
24-Pin (4mm
×
5mm) Plastic QFN
24-Pin (4mm
×
5mm) Plastic QFN
24-Pin (4mm
×
5mm) Plastic QFN
24-Pin (4mm
×
5mm) Plastic QFN
24-Pin (4mm
×
5mm) Plastic QFN
TEMPERATURE RANGE
0°C to 70°C
0°C to 70°C
–40°C to 85°C
–40°C to 85°C
–40°C to 125°C
–40°C to 125°C
LTC2970CUFD-1#TRPBF
LTC2970IUFD#TRPBF
LTC2970IUFD-1#TRPBF
LTC2970HUFD#TRPBF
LTC2970HUFD-1#TRPBF
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
2
29701fe
For more information
www.linear.com/LTC2970
LTC2970/LTC2970-1
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
12VIN
= 12V, V
DD
and REF pins floating unless otherwise indicated,
C
VDD
= 100nF and C
REF
= 100nF.
SYMBOL
I
V12
I
DD
V
LKO
V
DD
PARAMETER
12V
IN
Supply Current
V
DD
Supply Current
V
DD
Undervoltage Lockout
V
DD
Undervoltage Lockout Hysteresis
Supply Input Operating Range
Regulator Output Voltage
Regulator Output Voltage
Temperature Coefficient
Regulator Output Voltage Load
Regulation
Regulator Line Regulation
V
12VIN
V
REF
12V
IN
Supply Operating Range
Reference Output Voltage
Reference Voltage Temperature
Coefficient
Reference Overdrive Voltage Input
Range
ADC Characteristics
N_ADC
TUE_ADC
INL_ADC
DNL_ADC
V
IN_ADC
V
OS_ADC
GAIN_ADC
T
CONV_ADC
C
IN_ADC
F
IN_ADC
I
LEAK_ADC
N_I
OUT
INL_I
OUT
DNL_I
OUT
I
FS
-I
OUT
I
DRIFT
-I
OUT
I
OS
-I
OUT
Resolution
Total Unadjusted Error
Integral Nonlinearity
Differential Nonlinearity
Input Voltage Range
Offset Error
Offset Error Drift
Gain Error
Gain Error Drift
Conversion Time
Input Sampling Capacitance
Input Sampling Frequency
Input Leakage Current
Resolution (Guaranteed Monotonic)
Integral Nonlinearity
Differential Nonlinearity
Full-Scale Output Current
Output Current Drift
Offset Current
V
IOUTn
< V
DD
– 1.5V
V
IOUTn
< V
DD
– 1.5V
V
IOUTn
< V
DD
– 1.5V, DAC Code = 'hff
DAC Code = 'hff
DAC Code = 'h00
l
l
l
l
l
l
elecTrical characTerisTics
CONDITIONS
V
12VIN
= 12V, V
DD
Floating
V
DD
= 5V, V
12VIN
= V
DD
V
DD
Ramping-Down, V
12VIN
= V
DD
l
l
l
MIN
TYP
4.24
3.7
MAX
7.5
5
4.4
5.75
UNITS
mA
mA
V
mV
V
V
ppm/°C
ppm/mA
ppm/V
Power-Supply Characteristics
3.7
4.5
4.75
4.14
118
8V ≤ V
12VIN
≤ 15V, –1mA ≤ I
VDD
≤ 0
l
4.95
10
5.25
–1mA ≤ I
VDD
≤ 0
8V ≤ V
12VIN
≤ 15V, I
VDD
= 0mA
l
l
160
80
–5
8
1.229
2
1
1.5
–34
–63
15
Regulator Output Short-Circuit Current V
12VIN
= 12V, V
DD
= 0V
Voltage Reference Characteristics
mA
V
V
ppm/°C
V
N_ADC = 8.192V/16384
V
IN
= 3V, V
IN
= V
INn_xP
– V
INn_xM
(Note 3)
(Note 4)
(Note 7)
l
l
l
l
l
500
±0.5
–4.5
0
–1000
–316
0.19
2
4.5
±0.5
6
1000
±0.4
3
33.3
3
61.4
µV/LSB
%
LSB
LSB
V
µV
µV/°C
%
ppm/°C
ms
pF
kHz
±0.1
µA
Bits
±1
±1
LSB
LSB
µA
ppm/°C
±0.1
µA
29701fe
Full-Scale V
IN
= 6V
l
0V < V
IN
< 6V
l
IDAC Output Current Characteristics
8
–236
–255
32
–276
For more information
www.linear.com/LTC2970
3
LTC2970/LTC2970-1
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
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