TI UCC2895MDWREP

UCC2895-EP
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SCBS809F – DECEMBER 2005 – REVISED OCTOBER 2009
BiCMOS ADVANCED PHASE-SHIFT PWM CONTROLLER
Check for Samples: UCC2895-EP
FEATURES
1
•
•
•
•
•
•
•
•
•
•
Programmable Output Turn-On Delay
Adaptive Delay Set
Bidirectional Oscillator Synchronization
Capability for Voltage-Mode or Current-Mode
Control
Programmable Soft Start/Soft Stop and Chip
Disable Via a Single Pin
0% to 100% Duty-Cycle Control
7-MHz Error Amplifier
Operation to 1 MHz
Low Active Current Consumption (5 mA Typ at
500 kHz)
Very Low Current Consumption During
Undervoltage Lock Out (150 μA Typ)
SUPPORTS DEFENSE, AEROSPACE,
AND MEDICAL APPLICATIONS
•
•
•
•
•
•
•
Controlled Baseline
One Assembly/Test Site
One Fabrication Site
Available in Military (–55°C/125°C)
Temperature Range (1)
Extended Product Life Cycle
Extended Product-Change Notification
Product Traceability
DW PACKAGE
(TOP VIEW)
EAN
EAOUT
RAMP
REF
GND
SYNC
CT
RT
DELAB
DELCD
(1)
1
20
2
19
3
18
4
17
5
16
6
15
7
14
8
13
9
12
10
11
EAP
SS/DISB
OUTA
OUTB
PGND
VDD
OUTC
OUTD
CS
ADS
Additional temperature ranges available - contact factory
DESCRIPTION
The UCC2895-EP is a phase-shift pulse-width modulation (PWM) controller that implements control of a
full-bridge power stage by phase shifting the switching of one half bridge with respect to the other. It allows
constant frequency PWM in conjunction with resonant zero-voltage switching to provide high efficiency at high
frequencies. The device can be used either as a voltage-mode or current-mode controller.
While the UCC2895-EP maintains the functionality of the UC2875/6/7/8 family, it improves on that controller
family with additional features, such as enhanced control logic, adaptive delay set, and shutdown capability.
Since the device is built in BCDMOS, it operates with dramatically less supply current than its bipolar
counterparts. The UCC2895-EP can operate with a maximum clock frequency of 1 MHz.
The M-temp UCC2895-EP device is offered in the 20-pin SOIC (DW) package.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005–2009, Texas Instruments Incorporated
UCC2895-EP
SCBS809F – DECEMBER 2005 – REVISED OCTOBER 2009
www.ti.com
SIMPLIFIED APPLICATION DIAGRAM
UCC3895
1
EAN
2
EAOUT
3
Q1
EAP 20
7
SS/DISB
19
RAMP
OUTA
18
4
REF
OUTB
17
5
GND
PGND
16
6
SYNC
VCC
15
7
CT
OUTC
14
VOUT
AC
VIN
VBIAS
B
8
RT
9
10
OUTD
13
DELAB
CS
12
DELCD
ADS
11
D
UDG−98139
ORDERING INFORMATION
TA
–55°C to 125°C
(1)
2
PACKAGE
SOIC – DW
(1)
ORDERABLE PART NUMBER
UCC2895MDWREP
TOP-SIDE MARKING
UCC2895MEPG4
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at
www.ti.com/sc/package.
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SCBS809F – DECEMBER 2005 – REVISED OCTOBER 2009
Table 1. PIN DESCRIPTION
NAME
ADS
DESCRIPTION
Adaptive delay set.This function sets the ratio between the maximum and minimum programmed output delay dead
time. When ADS is connected directly to CS, no delay modulation occurs. Maximum delay modulation occurs when
ADS is grounded. In this case, delay time is four times longer when CS = 0 than when CS = 2 V (the peak current
threshold). ADS changes the output voltage on the delay (DELAB and DELCD) pins by:
VDEL + [0.75
(VCS * VADS)] ) 0.5 V
where VCS and VADS are in volts. ADS must be limited to between 0 V and 2.5 V and must be less than, or equal
to, CS. DELAB and DELCD also are clamped to a minimum of 0.5 V.
CS
Current sense. CS is the inverting input of the current-sense comparator, and the noninverting input of the
overcurrent comparator and the ADS amplifier. The CS signal is used for cycle-by-cycle current limiting in peak
current-mode control and for overcurrent protection in all cases with a secondary threshold for output shutdown. An
output disable initiated by an overcurrent fault also results in a restart cycle, called soft stop, with full soft start.
Oscillator timing capacitor (see Figure 3). The UCC2895-EP oscillator charges CT via a programmed current. The
waveform on CT is a sawtooth, with a peak voltage of 2.35 V. The approximate oscillator period is calculated by:
tOSC +
CT
5
RT
48
CT
) 120 ns
where CT is in farads, RT is in ohms, and tOSC is in seconds. CT can range from 100 pF to 880 pF. Note that a
large CT and a small RT combination results in extended fall times on the CT waveform. The increased fall time
increases the SYNC pulse width, thus, limiting the maximum phase shift between OUTA/ OUTB and OUTC/ OUTD
outputs, which limits the maximum duty cycle of the converter.
Delay programming between complementary outputs. DELAB programs the dead time between switching of OUTA
and OUTB, and DELCD programs the dead time between OUTC and OUTD. This delay is introduced between
complementary outputs in the same leg of the external bridge. The UCC2895-EP allows the user to select the delay
in which the resonant switching of the external power stages takes place. Separate delays are provided for the two
half bridges to accommodate differences in resonant capacitor charging currents. The delay in each stage is set
according to the formula:
DELAB, DELCD
tDELAY +
(25
10*12)
VDEL
RDEL
) 25 ns
where VDEL is in volts, RDEL is in ohms, and tDELAY is in seconds. DELAB and DELCD can source approximately
1 mA maximum. Delay resistors must be chosen so that this maximum is not exceeded. Programmable output
delay can be defeated by tying DELAB and/or DELCD to REF. For optimum performance, keep stray capacitance
on these pins at <10 pF.
EAN
Error amplifier negative. Inverting input to the error amplifier. Keep below 3.6 V for proper operation.
EAOUT
Error amplifier output. EAOUT also is connected internally to the noninverting input of the PWM comparator and the
no-load comparator. EAOUT is internally clamped to the soft-start voltage. The no-load comparator shuts down the
output stages when EAOUT falls below 500 mV and allows the outputs to turn on again when EAOUT rises above
600 mV.
EAP
Error amplifier positive. Noninverting input to the error amplifier. Keep below 3.6 V for proper operation.
GND
Ground. Chip ground for all circuits except the output stages.
OUTA
OUTB
OUTC
OUTD
Outputs. These outputs are 100-mA complementary MOS drivers and are optimized to drive FET driver circuits.
OUTA and OUTB are fully complementary (assuming no programmed delay). They operate near 50% duty cycle
and one-half the oscillating frequency. OUTA and OUTB are intended to drive one half-bridge circuit in an external
power stage. OUTC and OUTD drive the other half bridge and have the same characteristics as OUTA and OUTB.
OUTC is phase shifted with respect to OUTA, and OUTD is phase shifted with respect to OUTB. Note that
changing the phase relationship of OUTC and OUTD, with respect to OUTA and OUTB, requires other than the
nominal 50% duty ratio on OUTC and OUTD during those transients
PGND
Output stage ground. To keep output switching noise from critical analog circuits, the UCC2895-EP has two
different ground connections. PGND is the ground connection for the high-current output stages. Both GND and
PGND must be electrically tied together closely near the IC. Also, since PGND carries high current, board traces
must be low impedance.
RAMP
Inverting input of PWM comparator. RAMP receives either the CT waveform in voltage and average current-mode
controls, or the current signal (plus slope compensation) in peak current-mode control. An internal discharge
transistor is provided on RAMP, which is triggered during the oscillator dead time.
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Table 1. PIN DESCRIPTION (continued)
NAME
DESCRIPTION
Oscillator timing resistor (see Figure 3). The oscillator in the UCC2895-EP operates by charging an external timing
capacitor, CT, with a fixed current programmed by RT. RT current is calculated as:
RT
IRT (A) + 3 V
RT (W)
RT can range from 40 kΩ to 120 kΩ. Soft-start charging and discharging current also are programmed by IRT.
REF
5 V ± 1.2% voltage reference. REF supplies power to internal circuitry, and also can supply up to 5 mA to external
loads. The reference is shut down during undervoltage lockout, but is operational during all other disable modes.
For best performance, bypass with a 0.1-μF low ESR, low ESL capacitor to ground. Do not use more than 1.0 μF.
SS/DISB
Soft start/disable. SS/DISB combines two independent functions:
•
Disable mode. A rapid shutdown of the chip is accomplished by any one of the following: externally forcing
SS/DISB below 0.5 V, externally forcing REF below 4 V, VDD dropping below the UVLO threshold, or an
overcurrent fault is sensed (CS = 2.5 V).
In the case of REF pulled below 4 V or an UVLO condition, SS/DISB actively is pulled to ground via an internal
MOSFET switch. If an overcurrent is sensed, SS/DISB sinks a current of 10 × IRT until SS/DISB falls below
0.5 V.
Note that, if SS/DISB is externally forced below 0.5 V, the pin starts to source current equal to IRT. Also note
that the only time the part switches into the low IDD current mode is when the part is in undervoltage lockout.
•
Soft-start mode. After a fault or disable condition has passed and VDD is above the start threshold and/or
SS/DISB falls below 0.5 V during a soft stop, SS/DISB switches to a soft-start mode. The pin now sources
current equal to IRT. A user-selected capacitor on SS/DISB determines the soft start and soft-start time. In
addition, a resistor in parallel with the capacitor may be used, limiting the maximum voltage on SS/DISB. Note
that SS/DISB actively clamps the EAOUT voltage to approximately the SS/DISB voltage during both soft-start,
soft-stop, and disable conditions.
SYNC
Synchronization (see Figure 3). SYNC is bidirectional. When used as an output, SYNC can be used as a clock,
which is the same as the chip’s internal clock. When used as an input, SYNC overrides the chip’s internal oscillator
and acts as its clock signal. This bidirectional feature allows synchronization of multiple power supplies. SYNC also
internally discharges the CT capacitor and any filter capacitors that are present on RAMP. The internal SYNC
circuitry is level sensitive, with an input low threshold of 1.9 V and an input high threshold of 2.1 V. A resistor as
small as 3.9 kΩ may be tied between SYNC and GND to reduce the synchronization pulse width.
VDD
Power supply. VDD must be bypassed with a minimum of a 1.0-μF low ESR, low ESL capacitor to ground.
Absolute Maximum Ratings (1)
(2)
over operating free-air temperature range (unless otherwise noted)
MIN
Supply voltage
IDD < 10 mA
MAX
UNIT
17
V
Supply current
30
mA
REF current
15
mA
OUT current
100
mA
Analog inputs
EAP, EAN, EAOUT, RAMP, SYNC, ADS, CS, SS/DISB
–0.3
REF + 0.3
Drive outputs
OUTA, OUTB, OUTC, OUTD
–0.3
to VCC + 0.3
Power dissipation
(at TA = 25°C)
N package
1
DW package
V
W
650
mW
Tstg
Storage temperature range
–65
150
°C
TJ
Junction temperature range
–55
150
°C
300
°C
Lead temperature
(1)
(2)
4
Soldering, 10 s
Stresses beyond those 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 beyond those indicated under "recommended operating
conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Currents are positive into and negative out of the specified terminal.
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SCBS809F – DECEMBER 2005 – REVISED OCTOBER 2009
RECOMMENDED OPERATING CONDITIONS (1)
over operating free-air temperature range (unless otherwise noted)
MIN
VDD
Supply voltage
(2)
CVDD
Supply voltage bypass capacitor
CREF
Reference bypass capacitor (3)
CT
Timing capacitor (for 500-KHz switching frequency)
RT
Timing resistor (for 500-KHz switching frequency)
RDEL_AB
RDEL_CD
Delay resistor
TJ
(1)
(2)
(3)
(4)
NOM
10
Operating junction temperature
MAX
UNIT
16.5
V
10 x CREF
µF
0.1
(4)
4.7
µF
200
pF
82
2.5
40
kΩ
–55
125
°C
It is recommended that there be a single point grounded between GND and PGND directly under the device. There should be a
seperate ground plane associated with the GND pin and all components associated with pins 1 through 12 plus 19 and 20 be located
over this ground plane. Any connections associated with these pins to ground should be connected to this ground plane.
The VDD capacitor should be a low ESR, ESL ceramic capacitor located directly across the VDD and PGND pins. A larger bulk capacitor
should belocated as physically close as possible to the VDD pins.
The VREF capacitor should be a low ESR, ESL ceramic capacitor located directly across the REF and GND pins. If a larger capacitor is
desired for the VREF then it should be located near the VREF capacitor and connected to the VREF pin with a resistor of 51 Ω or greater.
The bulk capacitor on VDD must be a factor of 10 greater than the total VREF capacitance.
It is not recommended that the device operate under conditions beyond those specified in this table for extended periods of time.
Electrical Characteristics
VDD = 12 V, RT = 82 kΩ, CT = 220 pF, RDELAB = 10 kΩ, RDELCD = 10 kΩ, CREF = 0.1 μF, CVDD = 1 μF, No load at outputs,
TA = TJ, TA = –55°C to 125°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Start threshold
10.2
11
11.8
V
Stop threshold
8.2
9
9.8
V
1
2
3
V
150
250
μA
5
6
mA
UVLO
Hysteresis
Supply Current
Start-up current
VDD = 8 V
IDD active
VCC clamp voltage
IDD = 10 mA
16.5
17.5
18.5
TJ = 25°C
4.94
5
5.06
10 V < VDD < 17.5 V, 0 mA < IREF < 5 mA
4.85
5
5.15
10
20
V
Voltage Reference
Output voltage
Short-circuit current
REF = 0 V, TJ = 25°C
V
mA
Error Amplifier
Common-mode input voltage
–0.1
3.6
V
Offset voltage
–7
7
mV
Input bias current (EAP, EAN)
–1
1
μA
V
EAOUT VOH
EAP–EAN = 500 mV, IEAOUT = –0.5 mA
4
4.5
5
EAOUT VOL
EAP–EAN = 500 mV, IEAOUT = 0.5 mA
0
0.2
0.4
EAOUT source current
EAP–EAN = 500 mV, EAOUT = 2.5 V
1
1.5
mA
EAOUT sink current
EAP–EAN = –500 mV, EAOUT = 2.5 V
2.5
4.5
mA
75
85
dB
5
7
MHz
1.5
2.2
V/μs
No-load comparator turn-off threshold
0.45
0.5
0.55
V
No-load comparator turn-on threshold
0.55
0.6
0.69
V
0.035
0.1
0.165
V
Open-loop DC gain
Unity gain bandwidth (1)
Slew rate
EAN from 1 V to 0 V, EAP = 500 mV,
EAOUT from 0.5 V to 3 V (1)
No-load comparator hysteresis
(1)
V
Specified by design. Not production tested.
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Electrical Characteristics (continued)
VDD = 12 V, RT = 82 kΩ, CT = 220 pF, RDELAB = 10 kΩ, RDELCD = 10 kΩ, CREF = 0.1 μF, CVDD = 1 μF, No load at outputs,
TA = TJ, TA = –55°C to 125°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
473
500
527
kHz
2.5
5
%
Oscillator
Frequency
TJ = 25°C
Total variation
Line, Temperature (1)
SYNC VIH
2.05
2.1
2.32
V
SYNC VIL
1.85
1.9
1.95
V
4.1
4.5
5
V
0
0.5
1
V
85
135
ns
2.9
3
3.1
V
2.25
2.35
2.55
V
0
0.2
0.65
V
0.72
0.85
1.05
V
0
0.85
1.50
%
70
120
ns
SYNC VOH
ISYNC = –400 μA, CT = 2.6 V
SYNC VOL
ISYNC = 100 μA, CT = 0 V
SYNC output pulse width
SYNC load = 3.9 kΩ and 30 pF in parallel
RT voltage
CT peak voltage
CT valley voltage
PWM Comparator
EAOUT to RAMP/input offset voltage
RAMP = 0 V, DELAB = DELCD = REF
Minimum phase shift
(OUTA to OUTC, OUTB to OUTD)
RAMP = 0 V, EAOUT = 650 mV (2)
RAMP to OUTC/OUTD delay
RAMP from 0 V to 2.5 V, EAOUT = 1.2 V,
DELAB = DELCD = REF (3)
RAMP bias current
RAMP < 5 V, CT < 2.2 V
–5
RAMP sink current
RAMP = 5 V, CT < 2.6 V
12
5
19
μA
mA
Current Sense
20
μA
Peak current threshold
1.9
2
2.1
V
Overcurrent threshold
2.4
2.5
2.6
V
75
110
ns
–40
–35
–30
μA
CS bias current
CS to output delay
0 < CS< 2.5 V, 0 < ADS < 2.5 V
–4.5
CS from 0 to 2.3 V, DELAB = DELCD = REF
Soft Start/Shutdown
Soft-start source current
SS/DISB = 3 V, CS = 1.9 V
Soft-start sink current
SS/DISB = 3 V, CS = 2.6 V
Soft-start/disable comparator threshold
325
350
375
μA
0.44
0.5
0.56
V
0.45
0.5
0.55
V
Delay Set
DELAB/DELCD output voltage
ADS = CS = 0 V
ADS = 0 V, CS = 2 V
1.9
2
2.1
V
Output delay
ADS = CS = 0 V (3)
450
525
600
ns
ADS bias current
0 V < ADS < 2.5 V, 0 V < CS < 2.5 V
20
μA
(2)
(3)
(4)
6
(4)
–20
Minimum phase shift is defined as:
t f(OUTA) * t f(OUTC)
F + 200
tPERIOD
or
t f(OUTB) * t f(OUTD)
F + 200
tPERIOD
where:
tf(OUTA) = falling edge of OUTA signal
tf(OUTB) = falling edge of OUTB signal
tf(OUTC) = falling edge of OUTC signal
tf(OUTD) = falling edge of OUTD signal
t(PERIOD) = period of OUTA or OUTB signal
Output delay is measured between OUTA/OUTB or OUTC/OUTD. Output delay is shown in Figure 1 and Figure 2 , where:
tf(OUTA) = falling edge of OUTA signal
tr(OUTB) = rising edge of OUTB signal
Specified by design. Not production tested.
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Electrical Characteristics (continued)
VDD = 12 V, RT = 82 kΩ, CT = 220 pF, RDELAB = 10 kΩ, RDELCD = 10 kΩ, CREF = 0.1 μF, CVDD = 1 μF, No load at outputs,
TA = TJ, TA = –55°C to 125°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Output
VOH (all outputs)
IOUT = –10 mA, VDD to output
250
400
mV
VOL (all outputs)
IOUT = 10 mA
150
270
mV
Rise time
CLOAD = 100 pF
(5)
20
35
ns
Fall time
CLOAD = 100 pF (5)
20
35
ns
(5)
Specified by design. Not production tested.
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tPERIOD
OUTA(1)
OUTA(1)
tDELAY = tf(OUTA) – tr(OUTB)
tDELAY = tf(OUTA) – tf(OUTC)
OUTB(2)
OUTC(2)
(1)
Also applies to OUTB
(2)
Also applies to OUTD
Figure 1. OUTA/OUTC Output Delay
8
(1)
Also applies to OUTC
(2)
Also applies to OUTD
Figure 2. OUTA/OUTB Output Delay
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APPLICATION INFORMATION
Programming DELAB, DELCD, and Adaptive Delay Set (ADS)
The UCC2895-EP allows the user to set the delay between switch commands within each leg of the full-bridge
power circuit, according to the formula from the data sheet:
t DELAY +
(25
10 *12)
V DEL
R DEL
) 25 ns
For this equation, VDEL is determined in conjunction with the desire to utilize (or not utilize) the ADS feature from:
V DEL + [0.75
(V CS * V ADS)] ) 0.5 V
Figure 3 shows the resistors needed to program the delay periods and the ADS function.
UCC2895−EP
9
DELAB
10
DELCD
CS
12
ADS
11
RDELAB
RDELCD
Figure 3. Resistors Needed in Programming
The ADS allows the user to vary the delay times between switch commands within each of the converter’s two
legs. The delay-time modulation is implemented by connecting ADS (pin 11) to CS, GND, or a resistive divider
from CS to GND to set VADS. From the previous equation for VDEL, if ADS is tied to GND, VDEL rises in direct
proportion to VCS, causing a decrease in tDELAY as the load increases. In this condition, the maximum value of
VDEL is 2 V. If ADS is connected to a resistive divider between CS and GND, the term (VCS – VDS) becomes
smaller, reducing the level of VDEL. This decreases the amount of delay modulation. In the limit of ADS tied to
CS, VDEL = 0.5 V and no delay modulation occurs. In the case with maximum delay modulation (ADS = GND)
when the circuit goes from light load to heavy load, the variation of VDEL is from 0.5 V to 2 V. This causes the
delay times to vary by a 4:1 ratio as the load is changed.
The ability to program an adaptive delay is a desirable feature because the optimum delay time is a function of
the current flowing in the primary winding of the transformer, and can change by a factor of 10:1 or more as
circuit loading changes. Reference [1] delves into the many interrelated factors for choosing the optimum delay
times for the most efficient power conversion and illustrates an external circuit to enable ADS using the UC2879.
Implementing this adaptive feature is simplified in the UCC2895-EP controller, giving the user the ability to tailor
the delay times to suit a particular application, with a minimum of external parts.
[1] L. Balogh, "Design Review: 100W, 400 kHz, DC/DC Converter With Current Doubler Synchronous
Rectification Achieves 92% Efficiency," Unitrode Power Supply Design Seminar Manual, Unitrode Corporation,
1996, Topic 2.
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A = VADS/VCS RDELAY = 10 kW
A = 1.0
DELAY TIME (ns)
500
400
A = 0.8
300
A = 0.6
200
100
A = 0.4
A = 0.2
A = 0.1
0
0.5
1
1.5
2.0
2.5
CURRENT SENSE VOLTAGE (V)
Figure 4. Resistors Needed for Programming
CLOCK
RAMP
AND
COMP
PWM
SIGNAL
OUTPUT A
OUTPUT B
OUTPUT C
OUTPUT D
UDG−98138
Figure 5. UCC2895-EP Timing (No Output Delay Shown)
10
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IRT
RT
Q
8
CT
7
Q
R
SYNC
RAMP
3
EAN
R Q
DELAY B
D S Q
DELAY C
OUTA
9
DELAB
17
OUTB
+
ERROR
AMP
20
+
1
+
CURRENT−SENSE
COMPARATOR
14
NO−LOAD
COMPARATOR
R Q
DELAY D
+
12
2.5 V
IRT
+
HI = ON
10
DELCD
13
OUTD
16
PGND
11
ADS
4
REF
5
GND
ADAPTIVE DELAY
SET AMPLIFIER
+
REF
OUTC
0.5 V / 0.6 V
OVERCURRENT
COMPARATOR
SS
18
DELAY A
2
2V
CS
D S Q
VDD
+
EAP
Q
6
0.8 V
EAOUT
15
D S Q
OSC
8(IRT )
Q
S
Q
R
+
11 V/9 V
DISABLE
COMPARATOR
0.5 V
+
19
HI = ON
0.5 V
UVLO COMPARATOR
REF
REFERENCE OK
COMPARATOR
+
4V
10(IRT )
UDG−98140
Figure 6. Block Diagram
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Product Folder Link(s): UCC2895-EP
11
UCC2895-EP
SCBS809F – DECEMBER 2005 – REVISED OCTOBER 2009
www.ti.com
CIRCUIT DESCRIPTION
REF
8IRT
RT
RT
VREF
IRT
CT
2.5 V
S
CLOCK
Q
+
CT
+
0.2 V
R
SYNC
CLOCK
UDG−98141
Figure 7. Oscillator Block Diagram
REF
0.5 V
100 kΩ
75 kΩ
TO DELAY A
AND DELAY B
BLOCKS
+
CS
DELAB
+
100 kΩ
ADS
75 kΩ
REF
+
TO DELAY C
AND DELAY D
BLOCKS
DELCD
UDG−98142
Figure 8. ADS Block Diagram
12
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Copyright © 2005–2009, Texas Instruments Incorporated
Product Folder Link(s): UCC2895-EP
UCC2895-EP
www.ti.com
SCBS809F – DECEMBER 2005 – REVISED OCTOBER 2009
CIRCUIT DESCRIPTION (continued)
BUSED CURRENT
FROM ADS CIRCUIT
VREF
3.5 V
DELAB/CD
FROM PAD
DELAYED
CLOCK
SIGNAL
2.5 V
CLOCK
UDG−98143
Figure 9. Delay Block Diagram (One Delay Block Per Output)
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Product Folder Link(s): UCC2895-EP
13
UCC2895-EP
SCBS809F – DECEMBER 2005 – REVISED OCTOBER 2009
www.ti.com
TYPICAL CHARACTERISTICS
Vcs = 0 V
Vcs = 2 V
GAIN (dB)
2000
200
80
160
1400
1200
1000
800
60
120
40
80
20
40
600
400
PHASE MARGIN
(DEGREES)
1600
GAIN (dB)
OUTPUT DELAY (ns)
1800
PHASE MARGIN (5C)
100
200
0
10
0
20
30
0
40
0
1
RDEL (kW)
100
1000000
FREQUENCY (Hz)
Figure 10. Delay Programming (Characterizes Output Delay
Between A/B, C/D)
Figure 11. Error Amplifier Gain/Phase Margin
1
RT = 47 K
RT = 62 k
RT = 82 k
RT = 100 k
1600
0.95
FREQUENCY (kHz)
EAOUT TO RAMP OFFSET (V)
10000
0.9
0.85
1400
1200
1000
800
600
400
200
0.8
−60
−40
−20
0
20
40
60
80
100
0
120
100
TEMPERATURE (5C)
Figure 12. EAOUT to RAMP Offset Over Temperature
VDD = 10 V
VDD = 12 V
1000
CT (pF)
VDD = 15 V
Figure 13. Frequency vs RT/CT (Oscillator Frequency)
VDD = 10 V
VDD = 17 V
VDD = 12 V
VDD = 15 V
VDD = 17 V
13
9
12
11
IDD (mA)
IDD (mA)
8
7
6
10
9
8
7
6
5
5
4
4
0
400
800
1200
1600
0
400
OSCILLATOR FREQUENCY (kHz)
Figure 14. IDD vs VDD/Oscillator Frequency
(No Output Loading)
14
800
1200
1600
OSCILLATOR FREQUENCY (kHz)
Figure 15. IDD vs VDD/Oscillator Frequency
(With 0.1-nf Output Loads)
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Copyright © 2005–2009, Texas Instruments Incorporated
Product Folder Link(s): UCC2895-EP
PACKAGE OPTION ADDENDUM
www.ti.com
26-Oct-2009
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
UCC2895MDWREP
ACTIVE
SOIC
DW
20
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
V62/06614-01XE
ACTIVE
SOIC
DW
20
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
Lead/Ball Finish
MSL Peak Temp (3)
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
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In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
OTHER QUALIFIED VERSIONS OF UCC2895-EP :
UCC2895
• Catalog:
• Automotive: UCC2895-Q1
NOTE: Qualified Version Definitions:
- TI's standard catalog product
• Catalog
• Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects
Addendum-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
16-Mar-2012
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
UCC2895MDWREP
Package Package Pins
Type Drawing
SOIC
DW
20
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
2000
330.0
24.4
Pack Materials-Page 1
10.8
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
13.1
2.65
12.0
24.0
Q1
PACKAGE MATERIALS INFORMATION
www.ti.com
16-Mar-2012
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
UCC2895MDWREP
SOIC
DW
20
2000
346.0
346.0
41.0
Pack Materials-Page 2
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