EV1320QI
2A Source/Sink DDR Memory
Termination Converter
Description
Features
The EV1320QI is a DC to DC converter specifically
designed for memory termination applications. The
device offers high efficiency, up to 96%, while
providing a solution footprint similar to that of a linear
termination device.
•
•
•
•
The EV1320QI comes in a 3mm x 3mm x 0.55mm
QFN 16-pin package and requires only a small
number of external MLCC capacitors. The device is
designed to operate directly from the VDDQ supply
rail. No external divider or reference is required. The
EV1320QI provides a very stable output voltage
(VTT) which tracks VDDQ while sinking and sourcing
up to 2A of continuous output current. Up to 4
EV1320QI devices can be paralleled to source up to
8A of current. An ENABLE pin with output discharge
is available for S3 (suspend to RAM) states.
•
EV1320QI is specifically designed to meet the precise
voltage, fast transient requirements of present and
future high-performance, DDR2, DDR3, and low
power DDR4 JEDEC VTT requirements. Advanced
circuit techniques and high switching frequency
deliver high-quality, compact, non-isolated DC-DC
conversion.
•
•
•
•
•
•
•
•
High Efficiency, Up to 96%
80mm2 Total Solution Size
No External Inductor Required
JEDEC Compliant DDR2/3/QDR and Low Power
DDR 4 Solution
Enable Pin with Output Discharge to Support S3
(Suspend to RAM) Mode
Operates Directly from VDDQ
VOUT (VTT) Voltage Tracks VDDQ/2 ± 40mV
Source and Sink Up to 2A Continuous Current
Parallel Up to 4 Devices for 8A VTT Current
Programmable Soft Start/Soft Shutdown
Cost Effective Integrated Solution
Thermal Overload, Over Current, Short Circuit,
and Under-Voltage Protection
RoHS Compliant, MSL level 3, 260C Reflow
Applications
•
VTT Bus Termination for DDR2, DDR3, Low
Power DDR4, and QDR Memories
Efficiency vs. Output Current
98
96
EFFICIENCY (%)
94
92
90
88
86
VTT = 0.9V
84
VTT = 0.75V
82
VTT = 0.6V
CONDITIONS
AVIN = 3.0V
VDDQ = 2* VTT
80
0
Figure 1. Simplified Applications Circuit
0.2
0.4
0.6 0.8 1 1.2 1.4
OUTPUT CURRENT (A)
1.6
1.8
2
Figure 2. Highest Efficiency in Smallest Solution Size
www.enpirion.com
06831
2/13/2012
Rev: A
EV1320QI
Ordering Information
Part Number
EV1320QI
EV1320QI-E
Package Markings
EV1320QI
EV1320QI
Temp Rating (°C)
-40 to +85
Package Description
16-pin (3mm x 3mm x 0.55mm) QFN T&R
QFN Evaluation Board
Pin Assignments (Top View)
Figure 3: Pin Out Diagram (Top View)
NOTE A: NC pin should not to be electrically connected other pins or to any external signal, ground, or voltage. However,
it must be soldered to the PCB. Failure to follow this guideline may result in part malfunction or damage.
NOTE B: Shaded area highlights exposed metal below the package that is not to be mechanically or electrically
connected to the PCB. Refer to Figure 10 for details.
NOTE C: White ‘dot’ on top left is pin 1 indicator on top of the device package.
Pin Description
PIN
NAME
1
NC
2
AVIN
3
ENABLE
4
5
6
POK
SS
AGND
7, 8
PGND
9,10
11,12
13,14
15,16
C1N
VOUT
C1P
VDDQ
FUNCTION
NO CONNECT –– Do not electrically connect this pin to any other electrical signal. CAUTION:
May be internally connected.
Input Supply for internal controller and protection circuitry
Input Enable. Applying a logic high enables the output and initiates a soft-start. Applying a logic
low disables and discharges the output. ENABLE is internally tied to AVIN and ground through
a 100k resistor divider. Leaving ENABLE floating will result in voltage at half of AVIN.
VTT OK flag. This is an open drain output. Leave floating if unused.
Soft Start pin. Connect soft start capacitor between this pin and AGND.
Quiet ground for analog circuitry. Connect to the ground plane with a via next to the pin.
Power ground. Connect these pins to the ground electrode of the input and output filter
capacitors. See layout recommendations for more details.
Place 1 x 22µF and 2 x 10µF X5R 4V MLCC capacitors between C1N and C1P.
VTT voltage = ½ VDDQ.
Place 1 x 22µF and 2 x 10µF X5R 4V MLCC capacitors between C1N and C1P.
VDDQ voltage; VOUT (VTT) tracks this voltage.
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 2
Rev: A
EV1320QI
Absolute Maximum Ratings
CAUTION: Absolute Maximum ratings are stress ratings only. Functional operation beyond the recommended operating
conditions is not implied. Stress beyond the absolute maximum ratings may impair device life. Exposure to absolute
maximum rated conditions for extended periods may affect device reliability.
PARAMETER
SYMBOL
MIN
MAX
UNITS
Voltage on AVIN
-0.5
4.0
V
Voltage on C1P, C1N
-0.5
2.0
V
Voltage on AGND, PGND
-0.5
AVIN + 0.3
V
Voltage on VDDQ
-0.5
2.2
V
Voltage on VOUT
-0.5
VDDQ + 0.3
V
Voltage on POK
-0.5
AVIN + 0.3
V
Voltage on SS
-0.5
AVIN + 0.3
V
Voltage on ENABLE
-0.5
AVIN + 0.3
V
-65
150
°C
150
°C
260
°C
Storage Temperature Range
TSTG
Maximum Operating Junction Temperature
TJ-ABS Max
Reflow Temp, 10 Sec, MSL3 JEDEC J-STD-020A
ESD Rating (based on Human Body Model): All pins
2000
V
ESD Rating (based on Charged Device Model)
500
V
Recommended Operating Conditions
PARAMETER
SYMBOL
MIN
MAX
UNITS
Operating Junction Temperature
TJ
-40
+125
°C
Operating Ambient Temperature
TA
-40
+85
°C
Thermal Characteristics
PARAMETER
SYMBOL
TYP
UNITS
Thermal Resistance: Junction to Ambient (0 LFM) (Note 1)
θJA
50
°C/W
Thermal Shutdown
TSD
150
°C
Thermal Shutdown Hysteresis
TSDH
25
°C
Note 1: Based on 2oz. external copper layers and proper thermal design in line with EIJ/JEDEC JESD51-7 standard for
high thermal conductivity boards.
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 3
Rev: A
EV1320QI
Electrical Characteristics
NOTE: AVIN = 3.3V; VDDQ = 1.5V. Minimum and Maximum values are over operating ambient temperature range unless
otherwise noted. Typical values are at TA = 25°C.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
VDDQ voltage range
VDDQ
0.95
1.5
1.8
V
AVIN voltage range
VTT Tracking
Accuracy DC
(NOTE 2)
AVIN
3.0
3.3
3.465
V
VDDQ/
2 + 40
mV
∆VTT
AVIN=3.3V±5%
0A ≤ IVTT ≤ 2A
VDDQ/
2 -40
Under Voltage
Lockout; AVIN rising
VUVLO
2.5
V
Under Voltage
Lockout; AVIN falling
VUVLO
2.2
V
AVIN Shut-Down
Supply Current
IS
ENABLE=Low
600
μA
VDDQ Shut-Down
Supply Current
IS
ENABLE=Low
200
μA
AVIN No Load
Operating Current
IAVIN
AVIN=3.3V
6
mA
VDDQ No Load
Operating Current
IVDDQ
AVIN=3.3V
750
μA
Switching Frequency
FSW
500
625
750
kHz
POK Threshold
Sourcing Current
VOUT Rising
95
%
POK Threshold
Sourcing Current
VOUT Falling
85
%
ISINK = 1mA
POK Low Voltage
0.15
AVIN = 3.3V
POK High
POK Pin VOH Leakage
Current
Output Impedance
ROUT
Continuous Output
Current;
I_Max_Source
ΔVOUT/ΔILOAD
VDDQ=1.5V
AVIN=3.3V
Over Current Trip
Level
IOCP
AVIN=3.3V
Enable Threshold
Logic Low
ENA_VIL
Max voltage to ensure the converter
is disabled
Enable Threshold
Logic High
ENA_VIH
3.0V ≤ AVIN ≤ 3.46V
0.4
V
25
μA
20
-2
mΩ
2
±4.5
Enable Input Current
AVIN –
0.5
100
A
A
0.3
V
AVIN
V
200
µA
Note 2: The EV1320QI tracking accuracy is better than the JEDEC DDR2 and DDR3 VDDQ tracking specification of:
VDDQ*0.49 – 40mV to VDDQ*0.51+40mV.
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 4
Rev: A
EV1320QI
Typical Performance Curves
Efficiency vs. Output Current
98
96
96
94
94
EFFICIENCY (%)
EFFICIENCY (%)
Efficiency vs. Output Current
98
92
90
88
86
VTT = 0.9V
84
VTT = 0.75V
82
VTT = 0.6V
CONDITIONS
AVIN = 3.0V
VDDQ = 2* VTT
80
0
0.2
0.4
0.6 0.8 1 1.2 1.4
OUTPUT CURRENT (A)
1.6
1.8
2
92
VTT (V)
EFFICIENCY (%)
94
90
88
VTT = 0.75V
82
VTT = 0.6V
CONDITIONS
AVIN = 3.6V
VDDQ = 2* VTT
80
0
0.2
0.4
0.6 0.8 1 1.2 1.4
OUTPUT CURRENT (A)
1.6
1.8
2
VTT (V)
VTT (V)
06831
VTT = 0.9V
84
VTT = 0.75V
82
VTT = 0.6V
CONDITIONS
AVIN = 3.3V
VDDQ = 2* VTT
0.2
0.4
0.6 0.8 1 1.2 1.4
OUTPUT CURRENT (A)
1.6
1.8
2
1.00
0.95
Load = 0A
0.90
Load = 1A
0.85
Load = 2A
0.80
0.75
0.70
0.65
0.60
0.55
CONDITIONS
0.50
Load == 0A
AVIN
3.0V
0.45
0.40
1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80
VDDQ (V)
Output Voltage vs. Input Voltage
Output Voltage vs. Input Voltage
1.00
0.95
Load = 0A
0.90
Load = 1A
0.85
Load = 2A
0.80
0.75
0.70
0.65
0.60
0.55
CONDITIONS
0.50
Load == 0A
AVIN
3.3V
0.45
0.40
1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80
VDDQ (V)
©Enpirion 2012 all rights reserved, E&OE
86
Output Voltage vs. Input Voltage
96
84
88
0
98
VTT = 0.9V
90
80
Efficiency vs. Output Current
86
92
1.00
0.95
Load = 0A
0.90
Load = 1A
0.85
Load = 2A
0.80
0.75
0.70
0.65
0.60
0.55
CONDITIONS
0.50
Load == 0A
AVIN
3.6V
0.45
0.40
1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80
VDDQ (V)
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 5
Rev: A
EV1320QI
Typical Performance Curves (Continued)
Output Voltage vs. Output Current
Output Voltage vs. Output Current
0.80
0.64
0.63
VTT (V)
0.61
0.60
VTT (V)
CONDITIONS
AVIN = 3.3V
VDDQ = 1.2V
VTT = 0.6V
0.62
0.59
0.58
0.79
TA = -40 C
0.78
TA = 25 C
0.77
TA = 85 C
0.76
0.75
0.74
0.57
TA = -45 C
0.73
0.56
TA = 25 C
0.72
0.55
TA = 85 C
0.71
0.70
0.54
0
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8
OUTPUT CURRENT (A)
0
2
Output Voltage vs. Output Current
0.68
CONDITIONS
AVIN = 3.3V
VDDQ = 1.8V
VTT = 0.9V
0.91
0.90
CONDITIONS
AVIN=3.3V
VDDQ = 1.2V
0.66
0.64
VTT (V)
0.92
VTT (V)
2
0.70
0.93
0.89
LOAD = 0A
LOAD = 1A
LOAD = 2A
0.62
0.60
0.58
0.88
0.87
TA = -40 C
0.56
0.86
TA = 25 C
0.54
0.85
TA = 85 C
0.52
0.50
0.84
0
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8
OUTPUT CURRENT (A)
-40
2
Output Voltage vs. Temperature
-15
10
35
60
AMBIENT TEMPERATURE ( C)
85
Output Voltage vs. Temperature
0.85
1.00
0.83
CONDITIONS
AVIN=3.3V
VDDQ = 1.5V
0.81
0.79
LOAD = 0A
0.98
LOAD = 1A
0.96
CONDITIONS
AVIN=3.3V
VDDQ = 1.8V
0.94
LOAD = 2A
VTT (V)
VTT (V)
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8
OUTPUT CURRENT (A)
Output Voltage vs. Temperature
0.94
0.77
0.75
LOAD = 0A
LOAD = 1A
LOAD = 2A
0.92
0.90
0.73
0.88
0.71
0.86
0.69
0.84
0.67
0.82
0.65
0.80
-40
-15
10
35
60
AMBIENT TEMPERATURE ( C)
©Enpirion 2012 all rights reserved, E&OE
06831
CONDITIONS
AVIN = 3.3V
VDDQ = 1.5V
VTT = 0.75V
85
-40
Enpirion Confidential
2/13/2012
-15
10
35
60
AMBIENT TEMPERATURE ( C)
85
www.enpirion.com, Page 6
Rev: A
EV1320QI
Typical Performance Curves (Continued)
AVIN Input Current vs. Temperature
AVIN Input Current vs. Temperature
9
9
AVIN INPUT CURRENT (mA)
10
AVIN INPUT CURRENT (mA)
10
8
7
6
5
4
3
AVIN = 3.6V
2
AVIN = 3.3V
1
AVIN = 3.0V
CONDITIONS
VDDQ = 1.5V
VTT = 0.75V
8
7
6
5
4
0
-40
-15
10
35
60
AMBIENT TEMPERATURE( C)
3
VDDQ = 1.2V
2
VDDQ = 1.5V
1
VDDQ = 1.8V
0
85
-40
VDDQ INPUT CURRENT (µA)
VDDQ INPUT CURRENT (µA)
85
1000
AVIN = 3.6V
900
AVIN = 3.3V
800
AVIN = 3.0V
700
600
500
CONDITIONS
VDDQ = 1.5V
VTT = 0.75V
No Load
400
300
VTT = 0.6V
900
VTT = 0.75V
800
VTT = 0.9V
700
600
500
CONDITIONS
AVIN = 3.3V
VDDQ = 2*VTT
No Load
400
300
200
200
-40
-15
10
35
60
AMBIENT TEMPERATURE( C)
85
-40
VTT RISE TIME (µs)
700
650
600
AVIN = 3.6V
AVIN = 3.3V
AVIN = 3.0V
100
CONDITIONS
VDDQ = 1.5V
VTT = 0.75V
CONDITIONS
VDDQ = 1.5V
VTT = 0.75V
500
-40
-15
10
35
60
AMBIENT TEMPERATURE( C)
©Enpirion 2012 all rights reserved, E&OE
85
1000
750
550
-15
10
35
60
AMBIENT TEMPERATURE( C)
VTT Rise Time vs. Capacitance
Frequency vs. Temperature
OSCILLATOR FREQUENCY (kHz)
-15
10
35
60
AMBIENT TEMPERATURE( C)
VDDQ Input Current vs. Temperature
VDDQ Input Current vs. Temperature
1000
06831
CONDITIONS
AVIN = 3.3V
10
85
0.1
Enpirion Confidential
2/13/2012
1
10
SS CAPACITANCE (nF)
100
www.enpirion.com, Page 7
Rev: A
EV1320QI
Typical Performance Characteristics
Output Ripple at 1A Load
Output Ripple at 2A Load
VOUT
(AC Coupled)
VOUT
(AC Coupled)
CONDITIONS
AVIN = 3.3V
VDDQ = 1.5V
VTT = 0.75V
CIN, COUT, C1P = 22µF+2x10µF (0603)
Load = 1A
CONDITIONS
AVIN = 3.3V
VDDQ = 1.5V
VTT = 0.75V
CIN, COUT, C1P = 22µF+2x10µF (0603)
Load = 2A
Switching Waveform at 500mA
Switching Waveform at No Load
CH1:VDDQ
CH1:VDDQ
CH2:C1P
CH2:C1P
CH3:C1N
CH3:C1N
CH4:VTT
CH4:VTT
CONDITIONS
AVIN = 3.3V, VDDQ = 1.5V, VTT = 0.75V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
CONDITIONS
AVIN = 3.3V, VDDQ = 1.5V, VTT = 0.75V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
Switching Waveform at 1A
Switching Waveform at 2A
CH1:VDDQ
CH1:VDDQ
CH2:C1P
CH2:C1P
CH3:C1N
CH3:C1N
CH4:VTT
CH4:VTT
CONDITIONS
AVIN = 3.3V, VDDQ = 1.5V, VTT = 0.75V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
©Enpirion 2012 all rights reserved, E&OE
06831
CONDITIONS
AVIN = 3.3V, VDDQ = 1.5V, VTT = 0.75V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 8
Rev: A
EV1320QI
Typical Performance Characteristics (Continued)
Load Transient from 0 to 1A
Load Transient from 0 to 500mA
VDDQ
(AC Coupled)
VDDQ
(AC Coupled)
VTT
(AC Coupled)
VTT
(AC Coupled)
ΔVTT is due to ΔVDDQ
ΔVTT is due to ΔVDDQ
LOAD
CONDITIONS
AVIN = 3.3V
VDDQ = 1.5V
VTT = 0.75V
CIN, COUT, C1P = 22µF+2x10µF (0603)
LOAD
Load Transient from 0 to 2A
Load Transient from 0 to 1.5A
VDDQ
(AC Coupled)
VDDQ
(AC Coupled)
VTT
(AC Coupled)
VTT
(AC Coupled)
ΔVTT is due to ΔVDDQ
ΔVTT is due to ΔVDDQ
LOAD
CONDITIONS
AVIN = 3.3V
VDDQ = 1.5V
VTT = 0.75V
CIN, COUT, C1P = 22µF+2x10µF (0603)
CONDITIONS
AVIN = 3.3V
VDDQ = 1.5V
VTT = 0.75V
CIN, COUT, C1P = 22µF+2x10µF (0603)
LOAD
CONDITIONS
AVIN = 3.3V
VDDQ = 1.5V
VTT = 0.75V
CIN, COUT, C1P = 22µF+2x10µF (0603)
VDDQ to VTT Tracking with Line
VDDQ to VTT Tracking with Load
VDDQ
(AC Coupled)
VDDQ
(AC Coupled)
VTT
(AC Coupled)
ΔVTT is due to ΔVDDQ
VTT
(AC Coupled)
ΔVTT is due to ΔVDDQ
LOAD
©Enpirion 2012 all rights reserved, E&OE
06831
CONDITIONS
LOAD = 1Ω
AVIN = 3.3V, VDDQ = 1.8V, VTT = 0.9V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
CONDITIONS
AVIN = 3.3V, VDDQ = 1.5V, VTT = 0.75V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 9
Rev: A
EV1320QI
Typical Performance Characteristics (Continued)
Startup with POK at No Load
Startup with POK at 2A
ENABLE
ENABLE
VDDQ
VDDQ
VTT
VTT
POK
POK
CONDITIONS
No Load
AVIN = 3.3V, VDDQ = 1.2V, VTT = 0.6V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
CONDITIONS
No Load
AVIN = 3.3V, VDDQ = 1.2V, VTT = 0.6V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
Parallel VDDQ Startup with POK
Parallel Operation Startup at 4A
VDDQ (VDDQ#1 tied to VDDQ#2)
ENABLE
VDDQ (VDDQ#1 tied to VDDQ#2)
VTT (VTT#1 tied to VTT#2)
VTT (VTT#1 tied to VTT#2)
POK #1
Total Load = 4A (2A + 2A)
POK #2
CONDITIONS
LOAD = 4A
AVIN = 3.3V, VDDQ = 1.8V, VTT = 0.9V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
CONDITIONS
LOAD = 4A
AVIN = 3.3V, VDDQ = 1.8V, VTT = 0.9V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
Parallel Operation at 4A
Parallel Operation Load Transient
CH1: VDDQ (VDDQ#1 tied to VDDQ#2)
CH1: VDDQ (VDDQ#1 tied to VDDQ#2)
CH2: VTT (VTT#1 tied to VTT#2)
CH2:VTT (VTT#1 tied to VTT#2)
ΔVTT is due to ΔVDDQ
Total Load = 4A (2A + 2A)
Load #2: 2A
LOAD
Load #1: 2A
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
CONDITIONS
LOAD = 4A
AVIN = 3.3V, VDDQ = 1.5V, VTT = 0.75V,
CIN, COUT, C1P = 22µF+2x10µF (0603)
www.enpirion.com, Page 10
Rev: A
EV1320QI
Functional Block Diagram
Figure 4: Functional Block Diagram
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 11
Rev: A
EV1320QI
Functional Description
VDDQ/VTT Converter
The EV1320QI is designed to replace low efficiency
linear regulators as well as expensive switch-mode
DCDC memory terminations. The patented
EV1320QI architecture provides efficiencies up to
96% with a solution footprint similar to that of a
linear regulator.
VOUT (VTT) tracks ½VDDQ with ±40mV accuracy
and is compliant with DDR2/3/QDR and low power
DDR4 JEDEC memory termination requirements.
The EV1320QI tracks VDDQ directly so there is no
need for a separate reference voltage or resistor
divider network.
Table 1. Soft-Start Capacitance and Time Table
SS Capacitance (nF) VTT Rise Time (µs)
27
450
15
265
6.8
140
2.7
70
1
40
0.47
30
0.27
25
0.1
20
If a VREF signal is needed for the VTT termination,
it can be generated by an external VREF divider
circuit from VDDQ, as shown in Figure 5. The RVREF
resistors divide the VDDQ voltage by 2 and can be
used as the VREF signal. Choose high accuracy
resistors for RVREF. If more current is needed for
VREF, the divider signal may be buffered by a
voltage follower as shown in Figure 5. Be sure the
RVREF resistor values are negligible compared to the
input impedance of the voltage follower to ensure
VREF voltage accuracy.
NOTE: If a fault condition occurs during normal
operation the output is discharged through a 100Ω
resistor for a period of 1.5mS and then a soft start
cycle is initiated.
Enable Operation
The ENABLE pin provides a means to enable or
disable operation of the part. When enable is pulled
high the device will go through a soft start
sequence. When enable is pulled low such as if the
memory device enters S3 (suspend to RAM), the
output will be discharged through a 100Ω resistor.
Please note that if the equivalent load resistance is
lower than 100Ω, the output will discharge faster.
The ENABLE pin should not be left floating.
Power OK (POK)
The EV1320QI provides an open drain output to
indicate if the output voltage stays within nominally
+/- 10% of VDDQ/2. Within this range, the POK
output is allowed to be pulled high. Outside this
range, POK remains low. However, during
transitions such as enable/disable and fault restart
the POK output will not change state until the
transition is complete for enhanced noise immunity.
Figure 5. VREF Divider External Circuit
Soft-Start Operation
The EV1320QI has a programmable soft start. The
EV1320 can operate with AVIN on, ENABLE high,
and VDDQ ramped up and down. If, however,
VDDQ comes up first, and then the device is
enabled, the soft-start capacitor limits the rise of the
output (VTT). The output (VTT) ramp rate is
determined by the value of the soft start (SS)
capacitor, as shown in Table 1.
©Enpirion 2012 all rights reserved, E&OE
06831
The POK has 1mA sink capability for events where
it needs to feed a device with standard CMOS
inputs. When POK is pulled high, the pin leakage
current is as low as 20µA maximum over
temperature. This allows a large pull up resistor
such as 100kΩ to be used for minimal current
consumption in shutdown mode.
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 12
Rev: A
EV1320QI
Thermal Overload Protection
Thermal shutdown will disable operation when the
Junction temperature exceeds approximately
150ºC. Output will discharge through a 100 ohm
resistor for 1.5mS. If the thermal fault condition is
still present then the device will hiccup until temp
falls by 25°C. Once the junction temperature drops
by approximately 25ºC, the converter will re-start
with a normal soft-start.
Over-Current Protection
The overload function is achieved by sensing the
output voltage. An overload state is entered when
the device is out of soft start and the output voltage
drops below ~85% of VDDQ/2. When an OCP
condition is detected, the device is disabled, the
output is discharged through a 100 resistor for a
period of 1.5mS. After the 1.5mS discharge time
has expired, a soft start is initiated as described in
the soft start section. If an over current condition is
again detected the device will repeat the
discharge/soft start cycle in a hiccup manner as
long as the over current condition persists.
©Enpirion 2012 all rights reserved, E&OE
06831
Input Under-Voltage Lock-out
Internal circuits ensure that the converter will not
start switching until the AVIN voltage is above the
specified minimum voltage.
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 13
Rev: A
EV1320QI
Application Information
Figure 6. General Application Circuit
General Application Circuit
Figure 6 shows a typical application circuit for the
EV1320QI. The resistor before the AVIN capacitor
is optional, but recommended if AVIN supply is
noisy.
Power Up Sequence
During power up, neither ENABLE nor VDDQ
should be asserted before AVIN. There are two
common acceptable turn-on/off sequences for the
device. ENABLE can be tied to AVIN and come up
with it, and VDDQ can be ramped up and down as
needed. In this case, the output will attempt to track
VDDQ. Alternatively, VDDQ can be brought high
after AVIN is asserted, and the device can be
turned on and off by toggling the ENABLE pin. In
this case, the output will ramp up as determined by
the soft-start capacitor, and it will turn off as
described in “Enable Operation” section.
NOTE: The output filter capacitor section assumes
that there is additional decoupling on the VTT
island(s) of approximately 100µF per amp of VTT
current. If this VTT decoupling is not present,
additional bulk capacitance will be required on the
EV1320QI output.
Soft-Start ramp rate is set by choice of the soft start
capacitor (CSS) as described in the soft start
section.
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 14
Rev: A
EV1320QI
Parallel Operation
The architecture of the EV1320QI lends itself to
seem-less parallel operation. Up to 4 devices can
be paralleled to achieve a VTT current of up to 8A.
Input Capacitors
A 22µF 4V X5R MLCC and two 10µF 4V X5R
MLCC capacitors are required at the VDDQ input.
The 22µF capacitor must be placed at the position
closest to the VDDQ pins of the EV1320QI. Either
0603 or 0805 case size is acceptable. The
capacitors should be connected between VDDQ pin
and the PGND pin. Do not connect the capacitors
to the AGND terminal. Do not use Y5V or
equivalent dielectric capacitors. These capacitors
loose substantial capacitance with bias, frequency,
and temperature and are thus not appropriate for
use in DCDC converter applications. Refer to the
“Layout Recommendation” section for guidance on
placement and PCB routing.
Figure 7 shows an example circuit diagram for
parallel operation of three EV1320QIs. The
following guidelines must be followed for proper
parallel operation.
1. The VDDQ inputs should be connected to a
common VDDQ bus.
2. The VOUT connections should be
connected to a common VTT bus.
3. Each EV1320QI device must have its own
input and output capacitors connected close
to the device as described in the input and
output capacitor sections. The input and
output capacitors should be connected to
the local PGND pins on the respective
EV1320QI devices.
4. The C1N-C1P capacitors should only be
connected to their respective EV1320QI
devices. They should not be connected to
any common bus, VIN, VOUT, or any other
signal or plane.
5. All AVIN connections should be tied to a
common 3.3V supply rail. Each EV1320QI
should have its own AVIN filter resistor and
capacitor if required.
6. All ENABLE pins should be tied to a
common enable signal.
7. All soft start pins should be tied together
and a single soft start capacitor should be
used. Each device should NOT have its own
soft start capacitor.
8. All Analog ground (AGND) connections
should be tied together. The single soft start
capacitor should be connected to this
common AGND.
9. All Power ground (PGND) connections
should be tied together through a common
PGND plane. However, each input and
output capacitor compliment should be
connected to the local PGND pins on each
individual EV1320QI device.
10. The devices should be placed such that the
impedance in each path to the load is
equivalent to ensure current balance.
Output Capacitors
A 22µF 4V X5R MLCC and two 10µF 4V X5R
MLCC capacitors are required at the output. The
22µF capacitor must be placed at the position
closest to the VOUT pins of the EV1320QI. Either
0603 or 0805 case size is acceptable. The
capacitors should be connected between VOUT pin
and the PGND pin. Do not connect the capacitors
to the AGND terminal. Do not use Y5V or
equivalent dielectric capacitors. These capacitors
loose substantial capacitance with bias, frequency,
and temperature and are thus not appropriate for
use in DCDC converter applications.
This capacitor recommendation assumes that there
is additional bulk and decoupling capacitance at
VTT DIMM leads and the VTT islands. Ensure that
there is at least 100µF of bulk capacitance per amp
of VTT current. If there is not sufficient bulk
capacitance, add additional bulk capacitance to the
output of the EV1320QI. Refer to the “Layout
Recommendation” section for guidance on
placement and PCB routing.
C1N and C1P Capacitors
A 22µF 4V X5R MLCC and two 10µF 4V X5R
MLCC capacitors must be connected between the
C1N and C1P pins. The 22µF capacitor must be
placed in the position closest to the C1N and C1P
pins. The C1N and C1P pads should not be
connected to any other plane or trace. Capacitor
case size of 0805 or 0603 is acceptable. Do not
use Y5V or equivalent dielectric capacitors. These
capacitors loose substantial capacitance with bias,
frequency, and temperature and are thus not
appropriate for use in DCDC converter applications.
Refer to the “Layout Recommendation” section for
guidance on placement and PCB routing.
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 15
Rev: A
EV1320QI
Figure 7. Parallel Operation with Three EV1320QI
Technical Suport
Contact Enpirion Applications for additional support
regarding
the
use
of
this
product
(techsupport@enpirion.com).
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 16
Rev: A
EV1320QI
Thermal Considerations
PIN = POUT / η
Thermal considerations are important physical
limitations that cannot be avoided in the real world.
Whenever there are power losses in a system, the
heat that is generated by the power dissipation
needs to be accounted for.
PIN ≈ 1.2W / 0.926 ≈ 1.2959W
The power dissipation (PD) is the power loss in the
system and can be calculated by subtracting the
output power from the input power.
The Enpirion EV1320QI VDDQ/VTT Converter is
packaged in a 3x3x0.55mm 16-pin QFN package.
The recommended maximum junction temperature
for continuous operation is 125°C. Continuous
operation above 125°C may reduce long-term
reliability. The device has a thermal overload
protection circuit designed to turn off the device at
an approximate junction temperature value of
150°C.
PD = PIN – POUT
≈ 1.2959W – 1.2W ≈ 0.0959W
With the power dissipation known, the temperature
rise in the device may be estimated based on the
theta JA value (θJA). The θJA parameter estimates
how much the temperature will rise in the device for
every watt of power dissipation. The EV1320QI has
a θJA value of 50 ºC/W without airflow.
The EV1320QI is guaranteed to support the full 2A
output current up to 85°C ambient temperature.
The following example and calculations illustrate
the thermal performance of the EV1320QI.
Determine the change in temperature (ΔT) based
on PD and θJA.
ΔT = PD x θJA
Example:
ΔT ≈ 0.0959W x 50°C/W = 4.795°C ≈ 4.8°C
VDDQ = 1.2V
IOUT = 2A
The junction temperature (TJ) of the device is
approximately the ambient temperature (TA) plus
the change in temperature. We assume the initial
ambient temperature to be 25°C.
First calculate the output power.
TJ = TA + ΔT
POUT = VTT * IOUT = 0.6V x 2A = 1.2W
TJ ≈ 25°C + 4.8°C ≈ 29.8°C
Next, determine the input power based on the
efficiency (η) shown in Figure 8.
With 0.0959W dissipated into the device, the TJ will
be 29.8°C.
VTT = 0.6V
The maximum operating junction temperature
(TJMAX) of the device is 125°C, so the device can
operate at a higher ambient temperature. The
maximum ambient temperature (TAMAX) allowed can
be calculated.
Efficiency vs. Output Current
96
EFFICIENCY (%)
94
92
TAMAX = TJMAX – PD x θJA
90
≈ 125°C – 4.8°C ≈ 120.2°C
92.6%
88
The ambient temperature can actually rise by
another 95.2°C, bringing it to 120.2°C before the
device will reach TJMAX. This indicates that the
EV1320QI can support the full 2A output current
range up to approximately 120.2°C ambient
temperature given the input and output voltage
conditions. This allows the EV1320QI to guarantee
full 2A output current capability at 85°C with room
for margin. Note that the efficiency will be slightly
lower at higher temperatures and these calculations
are estimates.
86
84
82
VTT = 0.6V
CONDITIONS
AVIN = 3.0V
VDDQ = 2* VTT
80
0
0.2
0.4
0.6 0.8 1 1.2 1.4
OUTPUT CURRENT (A)
1.6
1.8
2
Figure 8: Efficiency vs. Output Current
For VDDQ = 1.2V, VTT = 0.6V at 2A, η ≈ 92.6%
η = POUT / PIN = 92.6% = 0.926
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 17
Rev: A
EV1320QI
Layout Recommendation
GND traces between the capacitors and the
EV1320QI should be as close to each other as
possible so that the gap between the two nodes is
minimized, even under the capacitors.
Recommendation 2: The C1N-C1P capacitors
should be placed as close to the C1N-C1P pins as
possible. Use large copper planes to minimize
resistance.
Recommendation 3: The system ground plane
should be the first layer immediately below the
surface layer. This ground plane should be
continuous and un-interrupted below the converter
and the input/output capacitors.
Recommendation 4: AVIN is the power supply for
the internal control circuits. It should be connected
to the 3.3V bus at a quiet point. An input filter for
AVIN (10µF with and optional 1Ω resistor) is
recommended.
Recommendation 5: Follow all the layout
recommendations as close as possible to optimize
performance. Enpirion provides schematic and
layout reviews for all customer designs. Please
contact local Sales Representatives for references
to Enpirion Applications Engineering support.
3.3V
ENABLE
1Ω
0402
1µF
0402
AVIN
AGND
POK100kΩ
0402
SS 15nF
VDDQ
AGND
0402
AVIN
C1P
VOUT
C1N
C1N
10µF
0603
PGND
PGND
SS
10µF
0603
EV1320
POK 3mm x 3mmVOUT
22µF
0603
22µF
0603
10µF
0603
10µF
0603
ENABLE
AGND
C1P
C1P
VDDQ
VDDQ
NC
C1N
22µF
0603
PGND
10µF
0603
10µF
0603
VTT
Figure 9: Typical Layout Recommendation (Top View)
Recommendation 1: Input and output filter
capacitors should be placed on the same side of
the PCB, and as close to the EV1320QI package
as possible. They should be connected to the
device with very short and wide traces. Do not use
thermal reliefs or spokes when connecting the
capacitor pads to the respective nodes. The +V and
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 18
Rev: A
EV1320QI
Recommended PCB Footprint
Figure 10: EV1320QI PCB Footprint (Top View)
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 19
Rev: A
EV1320QI
Package and Mechanical
Figure 11: EV1320QI Package Dimensions (Bottom View)
Contact Information
Enpirion, Inc.
Perryville III Corporate Park
53 Frontage Road - Suite 210
Hampton, NJ 08827 USA
Phone: 1.908.894.6000
Fax: 1.908.894.6090
Enpirion reserves the right to make changes in circuit design and/or specifications at any time without notice. Information furnished by Enpirion is
believed to be accurate and reliable. Enpirion assumes no responsibility for its use or for infringement of patents or other third party rights, which may
result from its use. Enpirion products are not authorized for use in nuclear control systems, as critical components in life support systems or equipment
used in hazardous environment without the express written authority from Enpirion
©Enpirion 2012 all rights reserved, E&OE
06831
Enpirion Confidential
2/13/2012
www.enpirion.com, Page 20
Rev: A
