AS1310-BTDT-27 [AMSCO]
Ultra Low Quiescent Current, Hysteretic DC-DC Step-Up Converter; 超低静态电流，滞回DC-DC升压转换器
| 型号： | AS1310-BTDT-27 |
| 厂家： | 
AMS(艾迈斯) |
| 描述： | Ultra Low Quiescent Current, Hysteretic DC-DC Step-Up Converter |
| 文件： | 总20页 (文件大小：1271K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
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Datasheet
AS1310
Ultra Low Quiescent Current, Hysteretic DC-DC Step-Up Converter
1 General Description
The AS1310 is an ultra low IQ hysteretic step-up DC-DC converter
optimized for light loads (60mA), where it achieves efficiencies of up
to 92%.
2 Key Features
Input voltage range: 0.7V to 3.6V
Fixed output voltage range: 1.8V to 3.3V
Output current: 60mA @ VIN=0.9V, VOUT=1.8V
Quiescent current: 1µA (typ.)
AS1310 operates from a 0.7V to 3.6V supply and supports output
voltages between 1.8V and 3.3V. Besides the available AS1310
standard variants any variant with output voltages in 50mV steps are
available. See Ordering Information on page 18 for more information.
Shutdown current: < 100nA
Up to 92% efficiency
If the input voltage exceeds the output voltage the device is in a
feed-through mode and the input is directly connected to the output
voltage.
Output disconnect in shutdown
Feedthrough mode when VIN > VOUT
Adjustable low battery detection
No exnal diode or transistor requed
Over temperature protectio
In light load operation, the device enters a sleep mode when most of
the internal operating blocks are turned off in order to save power.
This mode is active approximately 50µs after a current pulse
provided that the output is in regulation.
In order to save power the AS1310 features a shutdown mode,
where it draws less than 100nA. During shutdown mode the battery
is disconnected from the output.
TDFN (2x2) 8-pin package
3 Applications
The AS131n ideal solution for single and dual cell powered
devies as od lucose meters, remote controls, hearing aids,
wirelesmouse or any light-load application.
The AS1310 also offers adjustable low battery detection. If the
battery voltage decreases below the threshold defined by two
external resistors on pin LBI, the LBO output is pulled tloic low.
The AS1310 is available in a TDFN (2x2) 8-pin package
Figure 1. AS1310 Typical Application Diagrm
L
6.8µH
LX
3
VIN
0.7V to 3.6V
Low Battery Detect
6
8
VIN
LBO
R3
C1
22µF
R
R2
VOUT
1.8V to 3.3V
4
1
AS1310
VOUT
LBI
C2
22µF
5
7
On
Off
REF
EN
CREF
100nF
GND
2
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AS1310
Datasheet - Pin Assignments
4 Pin Assignments
Figure 2. Pin Assignments (Top View)
1
2
3
4
8
7
6
5
LBI
GND
LX
VIN
EN
AS1310
LBO
REF
VOUT
Exposed pad
4.1 Pin Descriptions
Table 1. Pin Descriptions
Pin Number
Pin Name
Description
Low Bry Comparator In.6V Threshold. May not be left floating. If connected to GND, LBO is
working as Power Output O
1
LBI
Ground
2
3
4
5
6
GND
LX
External Inuctor Connector.
Output Voltage. Decouple VOUT with a ceramic capacitor as close as possible to VOUT and GND.
Reference Connect a 100nF ceramic capacitor to this pin.
Lw Battery Comparator Output. Open-drain output.
VOUT
REF
LBO
Enable Pin. Logic controlled shutdown input.
1 Normal operation;
7
EN
0 = Shutdown; shutdown current <100nA.
Battery Voltage Input. Decouple VIN with a 22µF ceramic capacitor as close as possible to VIN and
GND.
8
9
VIN
NC
Exposed Pad. This pad is not connected internally. Can be left floating or connect to GND to achieve an
optimal thermal performance.
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AS1310
Datasheet - Absolute Maximum Ratings
5 Absolute Maximum Ratings
Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of
the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 4 is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
Parameter
Electrical Parameters
Min
Max
Units
Comments
VIN, VOUT, EN, LBI, LBO to GND
LX, REF to GND
-0.3
-0.3
-100
+5
VOUT + 0.3
100
V
V
Input Current (latch-up immunity)
mA
Norm: JEDEC 78
Electrostatic Discharge
Electrostatic Discharge HBM
Temperature Ranges and Storage Conditions
Thermal Resistance θJA
±2
kV
Norm: MIL 883 E method 3015
58
ºC/W
ºC
Junction Temperature
+125
+125
Storage Temperature Range
-55
ºC
The reflow peak soldering temperature (body
tempetre) specified is in accordance with IPC/
JEDEC -STD-020“Moisture/Reflow Sensitivity
Classication r Non-Hermetic Solid State Surface
Mount Devices”.
Package Body Temperature
+260
85
ºC
The ad finish for Pb-free leaded packages is matte
tin (100% Sn).
Humidity non-condensing
Moisture Sensitive Level
5
1
Represents a maximum floor life time of unlimited
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AS1310
Datasheet - Electrical Characteristics
6 Electrical Characteristics
All limits are guaranteed. The parameters with Min and Max values are guaranteed by production tests or SQC (Statistical Quality Control)
methods.
VIN = 1.5V, C1 = C2 = 22µF, CREF = 100nF, Typical values are at TAMB = +25ºC (unless otherwise specified). All limits are guaranteed. The
parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality Control) methods.
Table 3. Electrical Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Units
TAMB
Operating Temperature Range
-40
+85
°C
Input
VIN
Input Voltage Range
0.7
3.6
0.8
V
V
Minimum Startup Voltage
ILOAD = 1mA, TAMB = +25°C
0.7
Regulation
VOUT
Output Voltage Range
1.8
-2
3.
+2
+3
V
%
%
ILOAD = 10 mA, TAM= +25°C
ILOAD = 0mA
Output Voltage Tolerance
-3
VOUT Lockout Threshold1
Rising Edg
1.55
1.65
1.75
V
Operating Current
VOUT = 12xVOUTNOM,
REF = 0.99xVOUTNOM, TAMB = +2C
Quiescent Current VIN
100
nA
IQ
VOUT = 102xVON, REF = 0ON,
No load, TAMB +25°
Quiescent Current VOUT
0.8
1
1.2
µA
nA
ISHDN
Shutdown Current
TAMB = +25ºC
100
Switches
NMOS
PMOS
0.35
0.5
4.2
400
20
Ω
Ω
RON
T = 3V
NMOS maximum On-time
Peak Current Limit
Zero Crossing Current
3.6
320
5
4.8
480
35
µs
mA
mA
IPEAK
Enable, Reference
VENH
VENL
IEN
EN Input Volage Hgh
EN Input Voltage Low
EN InpBias urrent
REF Input Bias Current
0.7
V
V
0.1
100
100
EN = 3.6V, TAMB = +25°C
nA
nA
IREF
REF = 0.99xVOUTNOM, TAMB = +25°C
Low Battery & Power-K
VLBI
LBI Threshold
LBI Hysteresis
Falling Edge
0.57
0.6
25
0.63
V
mV
nA
ILBI
VLBO
ILBO
LBI Leakage Current
LBI = 3.6V, TAMB = +25°C
ILBO = 1mA
100
100
LBO Voltage Low2
LBO Leakage Current
Power-OK Threshold
20
mV
LBO = 3.6V, TAMB = +25°C
100
95
nA
%
LBI = 0V, Falling Edge
90
92.5
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AS1310
Datasheet - Electrical Characteristics
Table 3. Electrical Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Thermal Protection
Thermal Shutdown
10°C Hysteresis
150
°C
1. The regulator is in startup mode until this voltage is reached. Caution: Do not apply full load current until the device output > 1.75V
2. LBO goes low in startup mode as well as during normal operation if:
- The voltage at the LBI pin is below LBI threshold.
- The voltage at the LBI pin is below 0.1V and VOUT is below 92.5% of its nominal value.
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AS1310
Datasheet - Typical Operating Characteristics
7 Typical Operating Characteristics
TAMB = +25°C, unless otherwise specified.
Figure 3. Efficiency vs. Output Current; VOUT = 1.8V
Figure 4. Efficiency vs. Output Current; VOUT = 1.8V
90
90
L1: XPL2010-682M
L1: XPL7030-682M
85
85
80
75
70
65
60
55
80
75
70
65
60
55
50
45
4
Vin =0.9V
Vi0.9V
Vin =1.2V
Vin = 1.5V
50
Vin =1.2V
45
Vin = 1.5V
40
0.01
0.1
1
10
100
1000
.01
0.1
1
0
100
1000
1000
3
Output Current (mA)
Output Current (mA)
Figure 5. Efficiency vs. Output Current; VOUT = 3.0V
re 6. Efficiency vs. Outpt Current; VOUT = 3.0V
100
100
L1: XPL2010-682M
L1: XPL30-682M
95
95
90
85
80
75
70
65
60
55
50
45
40
90
8
80
75
0
65
60
Vin =0.9V
Vin =0.9V
Vin =1.2V
Vin =1.2
Vin = 1.5V
n =1.8V
Vin .4V
55
50
45
40
Vin = 1.5V
Vin =1.8V
Vin =2.4V
0.01
0.1
1
10
0
1000
0.01
0.1
1
10
100
Output Curret (mA)
Output Current (mA)
Figure 7. Efficiency vs. Input Voltage; VUT = 1.8V
Figure 8. Maximum Output Current vs. Input Voltage
100
180
L1: XPL2010-682M
95
160
140
120
100
80
90
85
80
75
0
65
60
55
50
60
40
Iout = 1mA
Iout=10mA
Iout=50mA
Vout =1.8V
20
0
Vout =3.0V
0.7
0.9
1.1
1.3
1.5
1.7
1.9
0
0.5
1
1.5
2
2.5
Input Voltage (V)
Input Voltage (V)
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AS1310
Datasheet - Typical Operating Characteristics
Figure 9. Start-up Voltage vs. Output Current
Figure 10. RON vs. Temperature
1
1
0.95
0.9
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0.85
0.8
0.75
0.7
0.65
0.6
PM OS
NM S
0.55
0.5
0
1
2
3
4
5
6
7
8
9
10
-40
-15
10
35
0
85
Output Current (mA)
Temperature (°C)
Figure 11. Output Voltage Ripple; VIN = 2V, VOUT = 3V,
Rload = 100Ω
5µs/Div
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AS1310
Datasheet - Detailed Description
8 Detailed Description
8.1 Hysteretic Boost Converter
Hysteretic boost converters are so called because comparators are the active elements used to determine on-off timing via current and voltage
measurements. There is no continuously operating fixed oscillator, providing an independent timing reference. As a result, a hysteretic or
comparator based converter has a very low quiescent current. In addition, because there is no fixed timing reference, the operating frequency is
determined by external component (inductor and capacitors) and also the loading on the output.
Ripple at the output is an essential operating component. A power cycle is initiated when the output regulated voltage drops below the nominal
value of VOUT (0.99 x VOUT).
Inductor current is monitored by the control loop, ensuring that operation is always dis-continuous.
The application circuit shown in Figure 1 will support many requirements. However, further optimization may be useful, and the following i
offered as a guide to changing the passive components to more closely match the end requirement.
8.1.1 Input Loop Timing
The input loop consists of the source dc supply, the input capacitor, the main inductor, and the N-channel power switchThe n timing of the N-
channel switch is determined by a peak current measurement or a maximum on time. In the AS1310, peak current is 400m(typand maximum
on time is 4.2µs (typ). Peak current measurement ensures that the on time varies as the input voltage varies. This imprts linregulation to the
converter.
The fixed on-time measurement is something of a safety feature to ensure thahe poweswitch is never permanently on. The fixed on-time is
independent of input voltage changes. As a result, no line regulation exists.
Figure 12. Simplified Boost DCDC Architecture
L1
SW2
VIN
VOUT
SW1
CIN
COUT
FB
RLOAD
IPK
GND
0V
0V
On time of the power switch (Fraday’Law) is given by:
LIPK
-----------------------------------------------------------------
TON
=
sec [volts, amps, ohms, Henry]
(EQ 1)
(EQ 2)
VIN – (IPKRSW1 + IPKRL1
)
Applying Min anMax alues and neglecting the resistive voltage drop across L1 and SW1;
LMIN IPK _ MIN
TON _ MIN
=
=
VIN _ MAX
LMAX IPK _ MAX
VIN _ MIN
TON _ MAX
(EQ 3)
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AS1310
Datasheet - Detailed Description
Figure 13. Simplified Voltage and Current Waveforms
V
0.99VOUT_NOM
VOUT
VOUT Ripple
VIND_TOFF
B
C
B
C
VIN
0
VIND_TON
D
A
D
T
TOFF TWAIT
TON
OFF TWAIT
IL
_on
Soff
IPK
0
T
S_o
SW1_off
T
Another important relationship is the “volt-seconds” law. xpressed as following:
VONTON = VOFFTOFF
(EQ 4)
Voltages are those measured across the ductoduring each time segment. Figure 13 shows this graphically with the shaded segments marked
“A & B”. Re-arranging (EQ 4):
T
V
OUT – VIN
------O---N---
TOFF
----------------------------
=
(EQ 5)
VIN
The time segment callTWAIT in Figure 13 is a measure of the “hold-up” time of the output capacitor. While the output voltage is above the
threshold (0.99xVUT), thoutput is assumed to be in regulation and no further switching occurs.
8.1.2 Inductor Choice Example
Fothe A10 IN_MIN = 0.9V, VOUT_MAX = 3.3V, (EQ 5) gives Ton=2.66TOFF
.
Let te maximum operating on-time = 1µs.
Note ththis is shorter than the minimum limit on-time of 3.6µs. Therefore from (EQ 5), TOFF = 0.376µs. Using (EQ 3), LMAX is obtained:
LMAX = 1.875µH. The nearest preferred value is 2.2µH.
This value provides the maximum energy storage for the chosen fixed on-time limit at the minimum VIN.
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AS1310
Datasheet - Detailed Description
Energy stored during the on time is given by:
2
E = 0.5L(IPK
)
Joules (Region A in Figure 13)
(EQ 6)
(EQ 7)
If the overall time period (TON + TOFF) is T, the power taken from the input is:
2
0.5L(IPK
)
--------------------------
Watts
PIN
=
T
Assume output power is 0.8 PIN to establish an initial value of operating period T.
WAIT is determined by the time taken for the output voltage to fall to 0.99xVOUT. The longer the wait time, the lower will be the supply current f
T
the converter. Longer wait times require increased output capacitance. Choose TWAIT = 10% T as a minimum starting point for maximum energy
transfer. For very low power load applications, choose TWAIT ≥ 50% T.
8.1.3 Output Loop Timing
The output loop consists of the main inductor, P-channel synchronous switch (or diode if fitted), output capacitor and load. When the inpuop is
interrupted, the voltage on the LX pin rises (Lenz’s Law). At the same time a comparator enables the synchronous switch, ad energy stored in
the inductor is transferred to the output capacitor and load. Inductor peak current supports the load and replenishes the harge ost from the
output capacitor. The magnitude of the current from the inductor is monitored, and as it approaches zero, the synchronous witch is turned off.
No switching action continues until the output voltage falls below the output reference point (0.99 x VOUT).
Output power is composed of the dc component (Region C in Figure 13):
IPKTOFF
I------------
PREGION_C = V
(EQ 8)
(EQ 9)
Output power is also composed of the inductor component (Region B in Fure 13), neglecting efficienclss:
2
0.5L(IPK
)
--------------------------
=
PREGION_B
T
Total power delivered to the load is the sum of (EQ 8) nd (EQ 9):
2
IPKTOFF 0.5LIPK
)
------- ------------ --------------------------
PTAL = VIN
+
(EQ 10)
(EQ 11)
2
T
T
From (EQ 3) (using nominal values) peak current is given by:
TONVIN
-----------------
L
IP
=
Substituting (EQ 11) into (EQ 10) and re-arranging:
V2INT
ON
---------------------
TOTAL
=
(0.9T)
(EQ 12)
2TL
0.9T incorporates a wait time TWAIT = 10%
Output power in terms of regulaed utput voltage and load resistance is:
V2
RLOAD
OUT
----------------
POUT
=
(EQ 13)
(EQ 14)
Combining (EQ 2) and (EQ 13):
V2INT
V2
OUT
ON
----------------
---------------------
(0.9T)η
=
RLOAD
2TL
Symboη reflects total energy loss between input and output and is approximately 0.8 for these calculations. Use (EQ 14) to plot duty cycle
(TON/T) changes for various output loadings and changes to VIN.
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AS1310
Datasheet - Detailed Description
8.1.4 Input Capacitor Selection
The input capacitor supports the triangular current during the on-time of the power switch, and maintains a broadly constant input voltage during
this time. The capacitance value is obtained from choosing a ripple voltage during the on-time of the power switch. Additionally, ripple voltage is
generated by the equivalent series resistance (ESR) of the capacitor. For worst case, use maximum peak current values from the datasheet.
IPEAKTON
-------------------------
CIN
=
(EQ 15)
VRIPPLE
Using TON = 1µs, and IPEAK = 480mA, and VRIPPLE = 50mV, EQ 15 yields:
CIN = 9.6µF
Nearest preferred would be 10µF.
VPK _ RIPPLE _ ESR = IPK RESR
(EQ
Typically, the ripple due to ESR is not dominant. ESR for the recommended capacitors (Murata GMR), ESR = 5mΩ to 10mΩ. For he A1310,
maximum peak current is 480mA. Ripple due to ESR is 2.4mV to 4.8mV.
Ripple at the input propagates through the common supply connections, and if too high in value can cause problems elewherin the system.
The input capacitance is an important component to get right.
8.1.5 Output Capacitor Selection
The output capacitor supports the triangular current during the off-time of the pwer swit(inductor discharge period), and also the load current
during the wait time (Region D in Figure 13) and on-time (Region A in Figure 13) othe power switch.
ILOAD (TO+TWAIT
(1− 0.99)VOUT _ NOM
)
COUT
=
(EQ 17)
Note: There is also a ripple component due to the equivalent series resistance (ESf the capacitor.
8.2 Summary
User Application Defines: VINmin, VINmaOUTmin, VOUTmax, ILOADmin, ILOADmax
Inductor Selection:
Select Max on-time = 0.5µs to 3µs for AS1310. Use (EQ 3) tcalculate inductor value.
Use (EQ 5) to determine off-time.
Use (EQ 6) to check that power delivery matches load rquirements assume 70% conversion efficiency.
Use (EQ 13) to find overall timing period value f T in VIN and max VOUT for maximum load conditions.
Input Capacitor Selection: Choose ripple value and use (EQ 14) to find the value.
Output Capacitor Selection: Deterine TWAIT via (EQ 6) or (EQ 13), and use (EQ 16) to find the value.
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AS1310
Datasheet - Application Information
9 Application Information
The AS1310 is available with fixed output voltages from 1.8V to 3.3V in 50mV steps.
Figure 14. AS1310 Block Diagram
0.7 to 3.6V
6.8µH
Zero
1.8V to 3.3V
Output
Input
Crossing
LX
VOUT
Detector
COUT
22µF
CIN
22µF
Startup
Circuitry
Driver
and
VIN
LBI
Control
Logic
–
+
LO
REF
Imax
Detection
VREF
A310
EN
CREF
100nF
GND
9.1 AS1310 Features
Shutdown. The part is in shutdown mode while the voltage at pin Eelow 0.1V and is active when the voltage is higher than 0.7V.
Note: EN can be driven above VIN or VOUT, as long as it limid to less than 3.6V.
Output Disconnect and Inrush Limiting. During hutdown VOUT is going to 0V and no current from the input source is running through
the device. This is true as long as the input voltage highr than the output voltage.
Feedthrough Mode. If the input voltage is highhan the output voltage the supply voltage is connected to the load through the device. To
guarantee a proper function of the AS13it is ot allowed that the supply exceeds the maximum allowed input voltage (3.6V).
In this feedthrough mode the quiescent current is 35µA (typ.). The device goes back into step-up mode when the oputput voltage is 4% (typ.)
below VOUTNOM.
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AS1310
Datasheet - Application Information
9.1.1 Power-OK and Low-Battery-Detect Functionality
LBO goes low in startup mode as well as during normal operation if:
- The voltage at the LBI pin is below LBI threshold (0.6V). This can be used to monitor the battery voltage.
- LBI pin is connected to GND and VOUT is below 92.5% of its nominal value. LBO works as a power-OK signal in this case.
The LBI pin can be connected to a resistive-divider to monitor a particular definable voltage and compare it with a 0.6V internal reference. If LBI
is connected to GND an internal resistive-divider is activated and connected to the output. Therefore, the Power-OK functionality can be realized
with no additional external components.
The Power-OK feature is not active during shutdown and provides a power-on-reset function that can operate down to VIN = 0.7V. A capacitor to
GND may be added to generate a power-on-reset delay. To obtain a logic-level output, connect a pull-up resistor R3 from pin LBO to pin VOUT.
Larger values for this resistor will help to minimize current consumption; a 100kΩ resistor is perfect for most applications (see Figure 16 on page
13).
For the circuit shown in the left of Figure 15, the input bias current into LBI is very low, permitting large-value resistor-divider networks while
maintaining accuracy. Place the resistor-divider network as close to the device as possible. Use a defined resistor for R2 and then calcuate R1
as:
VIN
----------
R1 = R2 ⋅
– 1
(EQ 18)
VLBI
Where:
VLBI is 0.6V ±30mV
Figure 15. Typical Application with Adjustable Battery Monitoring
L1
6.8µH
LX
3
VIN
0.7V to 3.6V
Low Battery Detect
8
6
VIN
O
R3
C1
22µF
R1
R2
VOUT
1.8V to 3.3V
4
1
AS1310
VOUT
LBI
C2
22µF
5
7
On
Off
REF
EN
CREF
100nF
GND
2
Figure 16. Typical Application with LBO orkinas Power-OK
L1
6.8µH
LX
3
VIN
0.7V to 3.6V
Low Battery Detect
8
6
VIN
LBO
R3
C1
22µF
VOUT
1.8V to 3.3V
4
1
AS1310
VOUT
LBI
C2
22µF
5
7
On
Off
REF
EN
CREF
100nF
GND
2
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AS1310
Datasheet - Application Information
9.1.2 Thermal Shutdown
To prevent the AS1310 from short-term misuse and overload conditions the chip includes a thermal overload protection. To block the normal
operation mode all switches will be turned off. The device is in thermal shutdown when the junction temperature exceeds 150°C. To resume the
normal operation the temperature has to drop below 140°C.
A good thermal path has to be provided to dissipate the heat generated within the package. Otherwise it’s not possible to operate the AS1310 at
its usable maximal power. To dissipate as much heat as possible from the package into a copper plane with as much area as possible, it’s
recommended to use multiple vias in the printed circuit board. It’s also recommended to solder the Exposed Pad (pin 9) to the GND plane.
Note: Continuing operation in thermal overload conditions may damage the device and is considered bad practice.
9.2 Always On Operation
In battery powered applications with long standby times as blood glucose meters, remote controls, soap dispensers, etc., a careful battery
management is required. Normally a complex power management control makes sure that the DCDC is only switched on, when it is relly
needed. With AS1310 this complex control can be saved completely, since the AS1310 is perfectly suited to support always-on operationof the
application. The efficiency at standby currents of e.g. 2µAs is around 45% (see Figure 17).
Figure 17. Efficiency vs. Output Current for Always ON Operation
100
L1: XPL2010-682M
90
80
70
60
50
40
30
20
in =1.V
10
V= 1.5V
0
0.001
0.01
0.1
1
10
100
Output Current (mA)
9.3 Component Selection
Only four components are required to complete thsign of the step-up converter. The low peak currents of the AS1310 allow the use of low
value, low profile inductors and tiny exteral ceramic capacitors.
9.4 Inductor Selection
For best efficiency, choose an ductowith high frequency core material, such as ferrite, to reduce core losses. The inductor should have low
DCR (DC resistance) to reuce thI²R losses, and must be able to handle the peak inductor current without saturating. A 6.8µH inductor with a
>500mA current rating nd <500mΩ DCR is recommended.
Table 4. RecomendeInductors
Pumber
XPL2010-682M
PL2014-682M
LPS3015-682M
LPS3314-682M
LPS4018-682M
XPL7030-682M
L
DCR
Current Rating
0.62A
Dimensions (L/W/T)
2.0x1.9x1.0 mm
2.0x2.0x1.4 mm
3.0x3.0x1.5 mm
3.3x3.3x1.3 mm
3.9x3.9x1.7 mm
7.0x7.0x3.0 mm
Manufacturer
6.8µH
6.8µH
6.8µH
6.8µH
6.8µH
6.8µH
421mΩ
287mΩ
300mΩ
240mΩ
150mΩ
59mΩ
0.59A
0.86A
Coilcraft
www.coilcraft.com
0.9A
1.3A
9.4A
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Revision 1.8
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AS1310
Datasheet - Application Information
Table 4. Recommended Inductors
Part Number
L
DCR
Current Rating
0.54A
Dimensions (L/W/T)
3.2x2.5x1.55 mm
3.0x3.0x1.1 mm
4.0x4.0x1.1 mm
Manufacturer
LQH32CN6R8M53L
LQH3NPN6R8NJ0L
LQH44PN6R8MJ0L
6.8µH
6.8µH
6.8µH
250mΩ
210mΩ
143mΩ
Murata
www.murata.com
0.7A
0.72A
9.5 Capacitor Selection
The convertor requires three capacitors. Ceramic X5R or X7R types will minimize ESL and ESR while maintaining capacitance at rated voltage
over temperature. The VIN capacitor should be 22µF. The VOUT capacitor should be between 22µF and 47µF. A larger output capacitor shoul
be used if lower peak to peak output voltage ripple is desired. A larger output capacitor will also improve load regulation on VOUT. See Table 5
for a list of capacitors for input and output capacitor selection.
Table 5. Recommended Input and Output Capacitors
Part Number
C
TC Code
X5R
Rated Voltage
6.3V
Dimensions (L/W/T)
0805, T=1.25mm
1206, T=1.6mm
anufacturer
GRM21BR60J226ME99
GRM31CR61C226KE15
GRM31CR60J475KA01
22µF
22µF
47µF
Murata
www.murata.com
X5R
16V
X5R
6.3V
1206, T=1.6mm
On the pin REF a 10nF capacitor with an Insulation resistance >1GΩ is recomended.
Table 6. Recommended Capacitors for REF
Insulatio
Resistance
Rated
Voltage
Part Number
C
TC Code
Diensions (L/W/T)
Manufacturer
GRM188R71C104KA01
GRM31CR61C226KE15
100nF
100nF
X7R
X7
>GΩ
>5GΩ
16V
0603, T=0.8mm
0805, T=1.25mm
Murata
www.murata.com
50
9.6 Layout Considerations
Relatively high peak currents of 480mA (max) late during normal operatin of the AS1310. Long printed circuit tracks can generate
additional ripple and noise that mask correct oation and prove di“de-bug” during production testing. Referring to Figure 1, the input
loop formed by C1, VIN and GND pins should be minimized. Similarlyutput loop formed by C2, VOUT and GND should also be minimized.
Ideally both loops should connect to GND in a “star” fashion. inally, it is important to return CREF to the GND pin directly.
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Revision 1.8
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AS1310
Datasheet
10 Package Drawings and Markings
The device is available in a TDFN (2x2) 8-pin package.
Figure 18. Drawings and Dimensions
X X X
A2
Symbol
A
Min
0.51
0.00
Nom
0.55
Max
0.60
0.05
A1
A3
L
0.02
0.15 REF
0.325
0.25
0.225
0.18
0.425
0.30
b
D
2.00 BSC
2.00 BSC
0.50 BSC
1.60
E
e
D2
E2
aaa
bbb
ccc
ddd
eee
fff
1.45
1.70
0.75
0.90
1.00
-
-
0.15
-
-
-
-
-
-
0.10
0.10
-
-
-
0.05
0.08
0.10
N
8
Nots:
1. Dimensioning & tolerancing conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters. Angles are in degrees.
3. Coplanarity applies to the exposed heat slug as well as the terminal.
4. Radius on terminal is optional.
5. N is the total number of terminals.
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Revision 1.8
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AS1310
Datasheet - Package Drawings and Markings
Revision History
Revision
1.0
Date
Owner
Description
Initial revision
Updated Detailed Description and Application Information sections
Detailed Description section updated
1.6
06 Mar, 2012
27 Apr, 2012
17 Aug, 2012
afe
1.7
Updated thermal resistance value and (EQ 17)
1.8
Note: Typos may not be explicitly mentioned under revision history.
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Revision 1.8
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AS1310
Datasheet - Ordering Information
11 Ordering Information
The device is available as the standard products shown in Table 7.
Table 7. Ordering Information
Ordering Code
AS1310-BTDT-18
AS1310-BTDT-20
AS1310-BTDT-25
AS1310-BTDT-27
AS1310-BTDT-30
Marking
A2
Output
1.8V
2.0V
2.5V
2.7V
3.0V
Description
Delivery Form
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Reel
Package
TDFN (2x2) 8-pin
TDFN (2x2) 8-pin
TDFN (2x2) 8-pin
TDFN (2x2) 8-pin
TDFN (2x2) 8pin
A8
A9
Ultra Low Quiescent Current,
Hysteretic DC-DC Step-Up Converter
A7
A6
AS1310-BTDT-331
AS1310-BTDT-xx2
1. On request
tbd
tbd
3.3V
tbd
Tape and Reel
Tape and Reel
TDFN (2x28-pin
TDFN (2x2) 8-pin
2. Non-standard devices are available between 1.8V and 3.3V in 50mV steps.
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Revision 1.8
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AS1310
Datasheet - Ordering Information
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