TI UCC3810DW

 SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
FEATURES
D Single Oscillator Synchronizes Two PWMs
D 150-µA Startup Supply Current
D 2-mA Operating Supply Current
D Operation to 1 MHz
D Internal Soft-Start
D Full-Cycle Fault Restart
D Internal Leading-Edge Blanking of the
D
D
D
DESCRIPTION
The UCC3810 is a high-speed BiCMOS controller
integrating two synchronized pulse width
modulators for use in off-line and dc-to-dc power
supplies. The UCC3810 family provides perfect
synchronization between two PWMs by usin g the
same oscillator. The oscillator’s sawtooth
waveform can be used for slope compensation if
required.
Current Sense Signal
1-A Totem Pole Outputs
75-ns Typical Response from Current Sense
to Output
1.5% Tolerance Voltage Reference
N PACKAGE
(TOP VIEW)
SYNC
CT
RT
FB1
COMP1
CS1
OUT1
GND
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
VCC
REF
ENABLE2
FB2
COMP2
CS2
OUT2
PWRGND
Using a toggle flip-flop to alternate between
modulators, the UCC3810 ensures that one PWM
does not slave, interfere, or otherwise affect the
other PWM. This toggle flip- flop also ensures that
each PWM is limited to 50% maximum duty cycle,
insuring adequate off-time to reset magnetic
elements. This device contains many of the same
elements of the UC3842 current mode controller
family, combined with the enhancements of the
UCC3802. This minimizes power supply parts
count. Enhancements include leading edge
blanking of the current sense signals, full cycle
fault restart, CMOS output drivers, and outputs
which remain low even when the supply voltage is
removed.
ERROR AMPLIFIER GAIN AND PHASE
vs
FREQUENCY
DW PACKAGE
(TOP VIEW)
SYNC
CT
RT
FB1
COMP1
CS1
OUT1
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VCC
REF
ENABLE2
FB2
COMP2
CS2
OUT2
PWRGND
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"&#"0 !)) '!!&"&#+
Copyright  2004, Texas Instruments Incorporated
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1
SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
ORDERING INFORMATION
PACKAGED DEVICES(1)
TJ
SOP (DW)
PDIP (N)
−40_C to 85_C
UCC2810DW (16)
UCC2810N (16)
0_C to 70_C
UCC3810DW (16)
UCC3810N (16)
(1) All packages are available taped and reeled (indicated by the R suffix on the device type e.g., UCC2810JR)
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted(1)(3)
UNIT
Supply voltage(2), VCC
11
V
Supply current, ICC
20
mA
Output peak current, OUT1, OUT2, 5% duty cycle
±1
A
Output energy, OUT1, OUT2, capacitive load
20
µJ
Analog inputs, FB1, FB2, CS1, CS2, SYNC
Operating junction temperature, TJ
Storage temperature range, Tstg
Lead temperature (soldering, 10 sec)
(1)
(2)
(3)
−0.3 to 6.3
V
150
_C
−65 to 150
_C
300
_C
Currents are positive into, negative out of the specified terminal. All voltages are with respect to GND.
In normal operation, VCC is powered through a current-limiting resistor. Absolute maximum of 11 V applies when driven from a low impedance
such that the VCC current does not exceed 20 mA.
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.
BLOCK DIAGRAM
UDG−92062−2
2
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SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
ELECTRICAL CHARACTERISTICS
All parameters are the same for both channels, −40_C ≤ TA ≤ 85_C for the UCC2810, 0_C ≤ TA ≤ 70_C for the
UCC3810, VCC = 10 V(1) ; RT = 150 kΩ, CT = 120 pF; no load; TA = TJ; (unless otherwise specified)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
4.925
5.000
5.075
4.85
5.00
5.10
5
30
UNIT
REFERENCE
VCC Output voltage
TJ = 25_C
TJ = full range,
0 mA ≤ IREF ≤ 5 mA
Load regulation
0 mA ≤ IREF ≤ 5 mA
Line regulation
UVLO stop threshold voltage,
0.5 V ≤ VCC ≤ VSHUNT
Output noise voltage(7)
10 Hz < f < 10 kHz,
TJ = 25_C
Long term stability(7)
TA = 125_C,
1000 hours
mV
12
IO(SC)Output short circuit current
V
235
µV
5
mV
−8
−25
mA
OSCILLATOR
fOSC Oscillator frequency(2)
RT = 30 kΩ
CT = 120 pF
760
880
1000
RT = 150 kΩ
CT = 120 pF
190
220
250
Temperature stability(7)
2.5%
Peak voltage
2.5
Valley voltage
0.05
Peak-to-peak amplitude
2.25
2.45
2.65
SYNC threshold voltage
0.80
1.65
2.20
SYNC input current
kHz
SYNC = 5 V
V
µA
30
ERROR AMPLIFIER
VFB
FB input voltage
IFB
FB input bias current
COMP = 2.5 V
2.44
Open loop voltage gain
60
fGAIN Unity gain bandwidth(7)
2.50
2.56
V
±1
µA
73
dB
2
MHz
ISINK Sink current, COMP
FB = 2.7 V,
COMP = 1 V
0.3
1.4
3.5
ISRCESource current, COMP
FB = 1.8 V,
COMP = 4 V
−0.2
−0.5
−0.8
Minimum duty cycle
Soft-start rise time, COMP
COMP = 0 V
FB = 1.8 V,
rise from 0.5 V to (REF − 1.5 V)
mA
0%
5
ms
(1) For UCC3810, adjust VCC above the start threshold before setting at 10 V.
4
(2) Oscillator frequency is twice the output frequency. f OSC +
RT CT
DV COMP
(3) Current sense gain A is defined by: A +
, 0 V ≤ VCS ≤ 0.8 V.
DV CS
(4) Parameter measured at trip point of latch with FB = 0 V.
(5) CS blank time is measured as the difference between the minimum non-zero on-time and the CS-to-OUT delay.
(6) Start threshold voltage and VCC internal zener voltage track each other.
(7) Ensured by design. Not production tested.
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3
SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
ELECTRICAL CHARACTERISTICS
All parameters are the same for both channels,−40_C ≤ TA ≤ 85_C for the UCC2810, 0_C ≤ TA ≤ 70_C for the
UCC3810, VCC = 10 V(1) ; RT = 150 kΩ, CT = 120 pF; no load; TA = TJ; (unless otherwise specified)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
1.20
1.55
1.80
V/V
0.9
1.0
CURRENT SENSE
Gain(3)
Maximum input signal(4)
ICS
COMP = 5 V
Input bias current, CS
CS steps from 0 V to 1.2 V,
COMP = 2.5 V
Propagation delay time (CS to OUT)
1.1
V
±200
nA
75
ns
Blank time, CS(5)
55
Overcurrent threshold voltage, CS
COMP-to-CS offset voltage
CS = 0 V
1.35
1.55
1.85
0.45
0.90
1.35
V
PWM
Maximum duty cycle(7)
Minimum on-time
RT = 150 kΩ,
CT = 120 pF
45%
49%
50%
RT = 30 kΩ,
CT = 120 pF
40%
45%
48%
CS = 1.2 V,
COMP = 5 V
130
ns
OUTPUT
IOUT = 20 mA
0.12
0.42
0.48
1.10
0.7
1.2
IOUT = −20 mA
0.15
0.42
IOUT = 200 mA
VOL Low-level output voltage
IOUT = 20 mA,
VOH High-level output voltage (VCC − OUT)
VCC = 0 V
IOUT = −200 mA
1.2
2.3
tR
Rise time, OUT
COUT = 1 nF
20
50
tF
Fall time, OUT
COUT = 1 nF
30
60
V
ns
UNDERVOLTAGE LOCKOUT (UVLO)
Start threshold voltage
9.6
11.3
13.2
Stop threshold voltage
7.1
8.3
9.5
Start-to-stop hysteresis
1.7
3.0
4.7
−20
−35
−55
µA
0.80
1.53
2.00
V
ENABLE2 input bias current
ENABLE2 = 0 V
ENABLE2 input threshold voltage
(1) For UCC3810, adjust VCC above the start threshold before setting at 10 V.
4
(2) Oscillator frequency is twice the output frequency. f OSC +
RT CT
DV COMP
(3) Current sense gain A, is defined by: A +
, 0 V ≤ VCS ≤ 0.8 V.
DV
CS
(4)
(5)
(6)
(7)
4
Parameter measured at trip point of latch with FB = 0 V.
CS blank time is measured as the difference between the minimum non-zero on-time and the CS-to-OUT delay.
Start threshold voltage and VCC internal zener voltage track each other.
Ensured by design. Not production tested.
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V
SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
ELECTRICAL CHARACTERISTICS
All parameters are the same for both channels, −40_C ≤ TA ≤ 85_C for the UCC2810, 0_C ≤ TA ≤ 70_C for the
UCC3810, VCC = 10 V(1) ; RT = 150 kΩ, CT = 120 pF; no load; TA = TJ; (unless otherwise specified)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
0.15
0.25
UNIT
OVERALL
Startup current
VCC < Start threshold voltage
Operating supply current, outputs off
VCC = 10 V,
FB = 2.75 V
2
3
VCC = 10 V,
CS = 0 V,
FB = 0 V,
RT = 150 kΩ
3.2
5.1
VCC = 10 V,
CS = 0 V,
FB = 0 V,
RT = 30 kΩ
8.5
14.5
11.0
12.9
14.0
0.4
1.2
Operating supply current, outputs on
VCC internal zener voltage(6)
ICC = 10 mA
VCC internal zener voltage minus start
threshold voltage
mA
V
(6) Start threshold voltage and VCC internal zener voltage track each other.
Terminal Functions
TERMINAL
NAME
NO.
I/O
DESCRIPTION
COMP1
5
O
COMP2
12
O
CS1
6
I
CS2
11
I
CT
2
O
The timing capacitor of the oscillator. Recommended values of CT are between 100 pF and 1 nF.
Connect the timing capacitor directly across CT and GND.
ENABLE2
14
I
A logic input which disables PWM 2 when low. This input has no effect on PWM 1. This input is internally pulled high. In most applications it can be left floating. In unusually noisy applications, the input
should be bypassed with a 1-nF ceramic capacitor. This input has TTL compatible thresholds.
FB1
4
I
FB2
13
I
GND
8
−
OUT1
7
O
OUT2
10
O
PWRGND
9
−
To separate noise from the critical control circuits, this part has two different ground connections:
GND and PWRGND. GND and PWRGND must be electrically connected together.
REF
15
O
The output of the 5-V reference. Bypass REF to GND with a ceramic capacitor ≥ 0.01-µF for best
performance.
RT
3
O
The oscillator charging current is set by the value of the resistor connected from RT to GND. This pin
is regulated to 1 V, but the actual charging current is 10 V/RT. Recommended values of RT are between 10 kΩ and 470 kΩ. For a given frequency, higher timing resistors give higher maximum duty
cycle and slightly lower overall power consumption.
SYNC
1
I
This logic input can be used to synchronize the oscillator to a free running oscillator in another part.
This pin is edge triggered with TTL thresholds, and requires at least a 10-ns-wide pulse. If unused,
this pin can be grounded, open circuited, or connected to REF.
VCC
16
I
The power input to the device. This pin supplies current to all functions including the high current
output stages and the precision reference. Therefore, it is critical that VCC be directly bypassed to
PWRGND with an 0.1-µF ceramic capacitor.
Low impedance output of the error amplifiers.
Current sense inputs to the PWM comparators. These inputs have leading edge blanking. For most
applications, no input filtering is required. Leading edge blanking disconnects the CS inputs from all
internal circuits for the first 55 ns of each PWM cycle. When used with very slow diodes or in other
applications where the current sense signal is unusually noisy, a small current-sense R-C filter may
be required.
The high impedance inverting inputs of the error amplifiers.
To separate noise from the critical control circuits, this part has two different ground connections:
GND and PWRGND. GND and PWRGND must be electrically connected together. However, use
care to avoid coupling noise into GND.
The high-current push-pull outputs of the PWM are intended to drive power MOSFET gates through
a small resistor. This resistor acts as both a current limiting resistor and as a damping impedance to
minimize ringing and overshoot.
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5
SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
APPLICATION INFORMATION
timing resistor
Supply current decreases with increased RT by the relationship:
DI CC + 11 V
RT
(1)
For more information, see the detailed oscillator block diagram.
leading edge blanking and current sense
Figure 1 shows how an external power stage is connected to the UCC3810. The gate of an external power
N-channel MOSFET is connected to OUT through a small current-limiting resistor. For most applications, a 10-Ω
resistor is adequate to limit peak current and also practical at damping resonances between the gate driver and
the MOSFET input reactance. Long gate lead length increases gate capacitance and mandates a higher series
gate resistor to damp the R-L-C tank formed by the lead, the MOSFET input reactance, and the device’s driver
output resistance.
The UCC3810 features internal leading edge blanking of the current-sense signal on both current sense inputs.
The blank time starts when OUT rises and continues for 55 ns. During that 55 ns period, the signal on CS is
ignored. For most PWM applications, this means that the CS input can be connected to the current-sense
resistor as shown in Figure 1. However, high speed grounding practices and short lead lengths are still required
for good performance.
Figure 1. Detailed Block Diagram
oscillator
The UCC3810 oscillator generates a sawtooth wave at CT. The sawtooth rise time is set by the resistor from
RT to GND. Since RT is biased at 1 V, the current through RT is 1 V/RT. The actual charging current is 10 times
higher. The fall time is set by an internal transistor on-resistance of approximately 100 Ω. During the fall time,
all outputs are off and the maximum duty cycle is reduced to below 50%. Larger timing capacitors increase the
discharge time and reduce frequency. However, the percentage maximum duty cycle is only a function of the
timing resistor RT, and the internal 100-Ω discharge resistance.
6
www.ti.com
SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
APPLICATION INFORMATION
error amplifier output stage
The UCC3810 error amplifiers are operational amplifiers with low-output resistance and high-input resistance.
The output stage of one error amplifier is shown in Figure 3. This output stage allows the error amplifier output
to swing close to GND and as high as one diode drop below 5 V with little loss in amplifier performance.
Figure 2. Oscillator
Figure 3. Error Amplifier Output Stage
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7
SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
TYPICAL CHARACTERISTICS
OSCILLATOR FREQUENCY
vs
TIMING RESISTANCE
ERROR AMPLIFIER GAIN AND PHASE
vs
FREQUENCY
Figure 5
Figure 4
MAXIMUM DUTY CYCLE
vs
TIMING RESISTANCE
OSCILLATOR FREQUENCY
vs
TEMPERATURE
Figure 6
8
Figure 7
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SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
TYPICAL CHARACTERISTICS
INPUT CURRENT
vs
OSCILLATOR FREQUENCY
MAXIMUM DUTY CYCLE
vs
FREQUENCY
Figure 8
Figure 9
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9
SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
UDG−94022
Figure 10. Typical Application
10
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SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
DW (R-PDSO-G**)
PLASTIC SMALL-OUTLINE PACKAGE
16 PINS SHOWN
0.050 (1,27)
0.020 (0,51)
0.014 (0,35)
16
0.010 (0,25) M
9
0.419 (10,65)
0.400 (10,15)
0.010 (0,25) NOM
0.299 (7,59)
0.291 (7,39)
Gage Plane
0.010 (0,25)
1
8
0.050 (1,27)
0.016 (0,40)
0°−ā 8°
A
Seating Plane
0.104 (2,65) MAX
0.012 (0,30)
0.004 (0,10)
PINS **
0.004 (0,10)
16
18
20
24
28
A MAX
0.410
(10,41)
0.462
(11,73)
0.510
(12,95)
0.610
(15,49)
0.710
(18,03)
A MIN
0.400
(10,16)
0.453
(11,51)
0.500
(12,70)
0.600
(15,24)
0.700
(17,78)
DIM
4040000 / E 08/01
NOTES: A.
B.
C.
D.
All linear dimensions are in inches (millimeters).
This drawing is subject to change without notice.
Body dimensions do not include mold flash or protrusion not to exceed 0.006 (0,15).
Falls within JEDEC MS-013
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11
SLUS162C − FEBRUARY 1999 − REVISED NOVEMBER 2004
N (R-PDIP-T**)
PLASTIC DUAL-IN-LINE PACKAGE
16 PINS SHOWN
PINS **
14
16
18
20
A MAX
0.775
(19,69)
0.775
(19,69)
0.920
(23,37)
0.975
(24,77)
A MIN
0.745
(18,92)
0.745
(18,92)
0.850
(21,59)
0.940
(23,88)
DIM
A
16
9
0.260 (6,60)
0.240 (6,10)
1
8
0.070 (1,78) MAX
0.035 (0,89) MAX
0.325 (8,26)
0.300 (7,62)
0.020 (0,51) MIN
0.015 (0,38)
Gauge Plane
0.200 (5,08) MAX
Seating Plane
0.010 (0,25) NOM
0.125 (3,18) MIN
0.100 (2,54)
0.021 (0,53)
0.015 (0,38)
0.430 (10,92) MAX
0.010 (0,25) M
14/18 PIN ONLY
4040049/D 02/00
NOTES: A. All linear dimensions are in inches (millimeters).
B. This drawing is subject to change without notice.
C. Falls within JEDEC MS-001 (20-pin package is shorter than MS-001).
12
www.ti.com
PACKAGE OPTION ADDENDUM
www.ti.com
8-Mar-2005
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
Lead/Ball Finish
MSL Peak Temp (3)
UCC2810DW
ACTIVE
SOIC
DW
16
40
None
CU NIPDAU
Level-2-220C-1 YEAR
UCC2810DWTR
ACTIVE
SOIC
DW
16
2000
None
CU NIPDAU
Level-2-220C-1 YEAR
UCC2810N
ACTIVE
PDIP
N
16
25
None
CU NIPDAU
Level-NA-NA-NA
UCC3810DW
ACTIVE
SOIC
DW
16
40
None
CU NIPDAU
Level-2-220C-1 YEAR
UCC3810DWTR
ACTIVE
SOIC
DW
16
2000
None
CU NIPDAU
Level-2-220C-1 YEAR
UCC3810DWTRG4
ACTIVE
SOIC
DW
16
2000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
UCC3810N
ACTIVE
PDIP
N
16
CU NIPDAU
Level-NA-NA-NA
25
None
(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 - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional
product content details.
None: Not yet available Lead (Pb-Free).
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.
Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens,
including bromine (Br) or antimony (Sb) above 0.1% of total product weight.
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry 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
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Addendum-Page 1
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