Linear Technology LTC2977 Demo Board: Octal Power Supply Manager [Requires DC1613] DC2028A DC2028A Data Sheet
Product codes
DC2028A
LTC2977
13
2977fa
pin FuncTions
PIN NAME
PIN NUMBER
PIN TYPE
DESCRIPTION
V
SENSEM6
1*
In
DC/DC Converter Differential (–) Output Voltage-6 Sensing Pin
V
SENSEP7
2*
In
DC/DC Converter Differential (+) Output Voltage or Current-7 Sensing Pin
V
SENSEM7
3*
In
DC/DC Converter Differential (–) Output Voltage or Current-7 Sensing Pin
V
OUT_EN0
4
Out
DC/DC Converter Enable-0 Pin. Output High Voltage Optionally Pulled Up to 12V by 5µA
V
OUT_EN1
5
Out
DC/DC Converter Enable-1 Pin. Output High Voltage Optionally Pulled Up to 12V by 5µA
V
OUT_EN2
6
Out
DC/DC Converter Enable-2 Pin. Output High Voltage Optionally Pulled Up to 12V by 5µA
V
OUT_EN3
7
Out
DC/DC Converter Enable-3 Pin. Output High Voltage Optionally Pulled Up to 12V by 5µA
V
OUT_EN4
8
Out
DC/DC Converter Open-Drain Pull-Down Output-4
V
OUT_EN5
9
Out
DC/DC Converter Open-Drain Pull-Down Output-5
V
OUT_EN6
10
Out
DC/DC Converter Open-Drain Pull-Down Output-6
V
OUT_EN7
11
Out
DC/DC Converter Open-Drain Pull-Down Output-7
V
IN_EN
12
0ut
DC/DC Converter V
IN
ENABLE Pin. Output High Voltage Optionally Pulled Up to 12V by 5µA
DNC
13
Do Not Connect Do Not Connect to This Pin
V
IN_SNS
14
In
V
IN
SENSE Input. This Voltage is Compared Against the V
IN
On and Off Voltage Thresholds in Order to
Determine When to Enable and Disable, Respectively, the Downstream DC/DC Converters.
V
PWR
15
In
V
PWR
Serves as the Unregulated Power Supply Input to the Chip (4.5V to 15V). If a 4.5V to 15V Supply
Voltage is Unavailable, Short V
PWR
to V
DD33
and Power the Chip Directly from a 3.3V Supply. Bypass to
GND with 0.1µF Capacitor.
V
DD33
16
In/Out
If Shorted to V
PWR
, it Serves as 3.13V to 3.47V Supply Input Pin. Otherwise, it is a 3.3V Internally
Regulated Voltage Output (Use 0.1µF Decoupling Capacitor to GND).
V
DD33
17
In
Input for Internal 2.5V Sub-Regulator. Short This Pin to Pin 16.
V
DD25
18
In/Out
2.5V Internally Regulated Voltage Output. Bypass to GND with a 0.1µF Capacitor.
WP
19
In
Digital Input. Write-Protect Input Pin, Active High.
PWRGD
20
Out
Power Good Open-Drain Output. Indicates When Outputs are Power Good. Can be Used as System
Power-On Reset.
SHARE_CLK
21
In/Out
Bidirectional Clock Sharing Pin. Connect a 5.49k Pull-Up Resistor to V
DD33
.
WDI/RESETB
22
In
Watchdog Timer Interrupt and Chip Reset Input. Connect a 10k Pull-Up Resistor to V
DD33
. Rising Edge
Resets Watchdog Counter. Holding This Pin Low for More Than t
RESETB
Resets the Chip.
FAULTB00
23
In/Out
Open-Drain Output and Digital Input. Active Low Bidirectional Fault Indicator-00. Connect a 10k Pull-Up
Resistor to V
DD33
.
FAULTB01
24
In/Out
Open-Drain Output and Digital Input. Active Low Bidirectional Fault Indicator-01. Connect a 10k Pull-Up
Resistor to V
DD33
.
FAULTB10
25
In/Out
Open-Drain Output and Digital Input. Active Low Bidirectional Fault Indicator-10. Connect a 10k Pull-Up
Resistor to V
DD33
.
FAULTB11
26
In/Out
Open-Drain Output and Digital Input. Active Low Bidirectional Fault Indicator-11. Connect a 10k Pull-Up
Resistor to V
DD33
.
SDA
27
In/Out
PMBus Bidirectional Serial Data Pin
SCL
28
In
PMBus Serial Clock Input Pin (400kHz Maximum)
ALERTB
29
Out
Open-Drain Output. Generates an Interrupt Request in a Fault/Warning Situation.
CONTROL0
30
In
Control Pin 0 Input
CONTROL1
31
In
Control Pin 1 Input
ASEL0
32
In
Ternary Address Select Pin 0 Input. Connect to V
DD33
, GND or Float to Encode 1 of 3 Logic States.
ASEL1
33
In
Ternary Address Select Pin 1 Input. Connect to V
DD33
, GND or Float to Encode 1 of 3 Logic States.
REFP
34
Out
Reference Voltage Output. Needs 0.1µF Decoupling Capacitor to REFM.
REFM
35
Out
Reference Return Pin. Needs 0.1µF Decoupling Capacitor to REFP.
V
SENSEP0
36*
In
DC/DC Converter Differential (+) Output Voltage-0 Sensing Pin
V
SENSEM0
37*
In
DC/DC Converter Differential (–) Output Voltage-0 Sensing Pin
V
DACM0
38
Out
DAC0 Return. Connect to Channel 0 DC/DC Converter’s GND Sense or Return to GND.
V
DACP0
39
Out
DAC0 Output
V
DACP1
40
Out
DAC1 Output