ENA1961 D

Ordering number : ENA1961
LV8773
Bi-CMOS LSI
PWM Constant-Current Control
Stepping Motor Driver
http://onsemi.com
Overview
The LV8773 is a 2-channel H-bridge driver IC, which supports forward, reverse, brake, and standby of a motor. It is
ideally suited for driving brushed DC motors and stepping motors used in office equipment and amusement
applications.
Features
• BiCDMOS process IC
• Low on resistance (upper side : 0.3Ω ; lower side : 0.25Ω ; total of upper and lower : 0.55Ω ; Ta = 25°C, IO = 2A)
• Motor current selectable in two steps
• Output short-circuit protection circuit (selectable from latch-type or auto-reset-type) incorporated
• Unusual condition warning output pins
• No control power supply required
Specifications
Absolute Maximum Ratings at Ta = 25°C
Parameter
Symbol
Supply voltage
VM max
Output peak current
IO peak
Output current
IO max
Logic input voltage
VIN
Conditions
Ratings
Unit
36
tw ≤ 10ms, duty 20%
V
2.5
A
2
A
-0.3 to +6
V
EMO1/EMO2 input voltage
Vemo/Vemo2
-0.3 to +6
V
Allowable power dissipation
Pd max1
1 unit
3.0
W
Pd max2
*
6.2
W
Operating temperature
Topr
-20 to +85
°C
Storage temperature
Tstg
-55 to +150
°C
* Specified circuit board : 90.0mm×90.0mm×1.6mm, glass epoxy 2-layer board.
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating
Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.
Semiconductor Components Industries, LLC, 2013
June, 2013
62211 SY 20110609-S00001 No.A1961-1/14
LV8773
Allowable Operating Ratings at Ta = 25°C
Parameter
Symbol
Conditions
Ratings
Unit
Supply voltage range
VM
9 to 32
V
Logic input voltage
VIN
0 to 5.5
V
VREF input voltage range
VREF
0 to 3
V
Electrical Characteristics at Ta = 25°C, VM = 24V, VREF = 1.5V
Parameter
Symbol
Ratings
Conditions
min
Standby mode current drain
IMst
typ
ST = “L”
Unit
max
100
400
μA
mA
Current drain
IM
ST = “H”, OE = “L”, with no load
3.2
5
VREG5 output voltage
Vreg5
IO = -1mA
4.5
5
5.5
V
Thermal shutdown temperature
TSD
Design guarantee
150
180
200
°C
Thermal hysteresis width
ΔTSD
Design guarantee
°C
40
Motor driver
Output on resistance
Ronu
IO = 2A, Upper-side on resistance
0.3
0.4
Ω
Rond
IO = 2A, Lower-side on resistance
0.25
0.33
Ω
50
μA
1.2
1.4
V
4
8
12
μA
30
50
70
μA
0.8
V
Output leakage current
IOleak
Diode forward voltage
VD
ID = -2A
Logic pin input current
IINL
VIN = 0.8V
IINH
VIN = 5V
Logic high-level input voltage
VINH
Logic low-level input voltage
VINL
2.0
V
Current setting comparator
Vtatt0
ATT = L
0.291
0.3
0.309
V
threshold voltage
Vtatt1
ATT = H
0.143
0.15
0.157
V
Chopping frequency
Fchop
Cchop = 220pF
36.3
45.4
54.5
kHz
CHOP pin charge/discharge current
Ichop
7
10
13
μA
(current attenuation rate switching)
Chopping oscillation circuit
Vtup
0.8
1
1.2
V
threshold voltage
Vtdown
0.4
0.5
0.6
V
VREF pin input current
Iref
VREF = 1.5V
μA
-0.5
Charge pump
VG output voltage
VG
Rise time
tONG
28
Oscillator frequency
Fosc
VG = 0.1μF
28.7
29.8
90
125
7
10
0.8
1
V
μS
200
150
kHz
400
mV
13
μA
1.2
V
Output short-circuit protection
EMO1/EMO2 pin saturation voltage
Vsatemo
Iemo = 1mA
CEM pin charge current
Icem
Vcem = 0V
CEM pin threshold voltage
Vtcem
Pd max - Ta
Allowable power dissipation, Pd max - W
8.0
6.2
6.0
Specified bord:90.0mm ¥ 90.0mm ¥ 1.6mm3
2 Layer glass epoxy
with substrate
4.0
1 unit
3.2
3.0
2.0
1.5
0
– 20
0
20
40
60
80
100
Ambient temperature, Ta - C
No.A1961-2/14
LV8773
Package Dimensions
unit : mm (typ)
3241A
26.75
(20.0)
28
11.2
12.7
15
(8.4)
1
14
3.6
(4.0)
1.0
0.4
(R1.7)
(1.81)
1.78
0.6
SANYO : DIP28HC(500mil)
Pin Assignment
CP2 1
28
VM
CP1 2
27
VG
VREG5 3
26
OUT1A
ATT 4
25
PGND
EMO1 5
24
VM1
CEM 6
23
RF1
EMM 7
22 OUT1B
LV8773
CHOP 8
21 OUT2A
EMO2 9
20 RF2
VM2
DC22 10
19
DC21 11
18 PGND
DC12 12
17 OUT2B
DC11 13
16 GND
15 VREF
ST 14
Top view
No.A1961-3/14
VREG5
PGND
VM
GND
VREF
+
1.5V -
24V
+
-
+
-
CHOP
Oscillation
circuit
Regulator
ST
Charge pump
ATT
Output preamplifier stage
RF1
+
OUT1A
OUT1B VMI
VM2 OUT2A
DC11 DC12
+
RF2
CEM
Overcurrent
protection circuit
TSD
OUT2B
DC21 DC22 EMM
Output control logic
Output preamplifier stage
VG
Output preamplifier stage
CP2
Output preamplifier stage
CP1
EMO2
EMO1
5V
LV8773
Block Diagram
No.A1961-4/14
LV8773
Pin Functions
Pin No.
Pin Name
Pin Function
4
ATT2
Motor holding current switching pin.
7
EMM
Output short-circuit protection mode
10
DC22
Channel 2 output control input pin 2
11
DC21
Channel 2 output control input pin 1
12
DC12
Channel 1 output control input pin 2
13
DC11
Channel 1 output control input pin 1
Equivalent Circuit
VREG5
switching pin.
10kΩ
100kΩ
GND
14
ST
Chip enable pin.
VREG5
20kΩ
10kΩ
80kΩ
GND
17
OUT2B
Channel 2 OUTB output pin.
18, 25
PGND
Power system ground.
19
VM2
Channel 2 motor power supply
20
RF2
21
OUT2A
Channel 2 OUTA output pin.
22
OUT1B
Channel 1 OUTB output pin.
23
RF1
Channel 1 current-sense resistor
19
24
connection pin.
Channel 2 current-sense resistor
connection pin.
24
VM1
Channel 1 motor power supply pin.
26
OUT1A
Channel 1 OUTA output pin.
17
22
21
26
connection pin.
25 18
20
23
GND
27
VG
Charge pump capacitor connection pin.
28
VM
Motor power supply connection pin.
1
CP2
Charge pump capacitor connection pin.
2
CP1
Charge pump capacitor connection pin.
2
28
1
27
VREG5
GND
16
GND
Ground.
Continued on next page.
No.A1961-5/14
LV8773
Continued from preceding page.
Pin No.
15
Pin Name
VREF
Pin Function
Constant current control reference
voltage input pin.
Equivalent Circuit
VREG5
GND
3
VREG5
Internal power supply capacitor
connection pin.
VM
GND
5
EMO1
Channel 1 output short-circuit state
VREG5
warning output pin.
9
EMO2
Channel 2 output short-circuit state
warning output pin.
GND
6
CEM
Pin to connect the output short-circuit
VREG5
state detection time setting capacitor
GND
8
CHOP
Copping frequency setting capacitor
connection pin.
VREG5
GND
No.A1961-6/14
LV8773
Description of operation
(1) Chip enable function
This IC is switched between standby and operating mode by setting the ST pin. In standby mode, the IC is set to
power-save mode and all logic is reset. In addition, the internal regulator circuit and charge pump circuit do not
operate in standby mode.
ST
Mode
Internal regulator
Low or Open
Standby mode
Standby
Charge pump
Standby
High
Operating mode
Operating
Operating
(2) Output control logic
input
output
mode
DC11(21)
DC12(22)
OUT1(2)A
OUT1(2)B
L
L
OFF
OFF
H
L
H
L
CW ( Forward )
L
H
L
H
CCW ( reverse )
H
H
L
L
brake
Stand-by
(3) Blanking period
If, when exercising PWM constant-current chopping control over the motor current, the mode is switched from decay
to charge, the recovery current of the parasitic diode may flow to the current sensing resistance, causing noise to be
carried on the current sensing resistance pin, and this may result in erroneous detection. To prevent this erroneous
detection, a blanking period is provided to prevent the noise occurring during mode switching from being received.
During this period, the mode is not switched from charge to decay even if noise is carried on the current sensing
resistance pin.
This IC is the blanking time is fixed at approximately 2μs.
(4) Chopping frequency setting
For constant-current control, this IC performs chopping operations at the frequency determined by the capacitor
(Cchop) connected between the CHOP pin and GND.
The chopping frequency is set as shown below by the capacitor (Cchop) connected between the CHOP pin and GND.
Fchop = Ichop/ (Cchop × Vtchop × 2) (Hz)
Ichop : Capacitor charge/discharge current, typ 10μA
Vtchop : Charge/discharge hysteresis voltage (Vtup-Vtdown), typ 0.5V
For instance, when Cchop is 220pF, the chopping frequency will be as follows :
Fchop = 10μA/ (220pF × 0.5V × 2) = 45.4kHz
No.A1961-7/14
LV8773
(5) Setting constant-current control
When the current of the motor reaches up to a set current by setting the output current, this IC does the short brake
control by the automatic operation so that the current should not increase more than it.
Set current
BLANKING time
Coil current
Chopping cycle
Current mode
CHARGE
SLOW
Based on the voltage input to the VREF pin and the resistance connected between RF and GND, the output current
that is subject to the constant-current control is set using the calculation formula below :
IOUT = (VREF/5)/RF resistance
* The above setting is the output current at 100% of each excitation mode.
The voltage input to the VREF pin can be switched to two-step settings depending on the statuses of the ATT.
Attenuation function for VREF input voltage
ATT
Current setting reference voltage attenuation ratio
Low
100%
High
50%
The formula used to calculate the output current when using the function for attenuating the VREF input voltage is
given below.
IOUT = (VREF/5) × (attenuation ratio)/RF resistance
Example : At VREF of 1.5V, a reference voltage setting of 100% (ATT = L) and an RF resistance of 0.3Ω, the output
current is set as shown below.
IOUT = 1.5V/5 × 100%/0.3Ω = 1.0A
If, in this state, ATT = H will be as follows :
IOUT = 1.0A × 50% = 500mA
No.A1961-8/14
LV8773
(6) Typical current waveform in each excitation mode when stepping motor parallel input control
2-phase excitation (CW mode)
DC11
DC12
DC21
DC22
(%)
100
0
I1
-100
(%)
100
0
I2
-100
1-2 phase excitation full torque (CW mode)
DC11
DC21
DC12
DC22
(%)
100
l1
0
-100
(%)
100
l2
0
-100
No.A1961-9/14
LV8773
(7) Output short-circuit protection function
This IC incorporates an output short-circuit protection circuit that, when the output has been shorted by an event such
as shorting to power or shorting to ground, sets the output to the standby mode and turns on the warning output in
order to prevent the IC from being damaged. In the channels 1 and 2 operate independently. (Even if the output of
channel 1 has been short-circuited, channel 2 will operate normally.)
(7-1) Output short-circuit protection operation changeover function
Changeover to the output short-circuit protection of IC is made by the setting of EMM pin.
EMM
State
Low or Open
Latch method
High
Auto reset method
(7-2) Latch type
In the latch mode, when the output current exceeds the detection current level, the output is turned OFF, and this state
is held.
The detection of the output short-circuited state by the IC causes the output short-circuit protection circuit to be
activated.
When the short-circuited state continues for the period of time set using the internal timer (approximately 2μs), the
output in which the short-circuiting has been detected is first set to OFF. After this, the output is set to ON again as
soon as the timer latch time (Tcem) described later has been exceeded, and if the short-circuited state is still detected,
all the outputs of the channel concerned are switched to the standby mode, and this state is held.
This state is released by setting ST to low.
Output ON
H-bridge
output state
Output ON
Output OFF
Standby state
Threshold voltage
CEM voltage
Short-circuit
detection state
Short- Release
circuit
Short-circuit
Internal counter
1st counter
start
1st counter 1st counter
stop
start
1st counter
end
2nd counter
start
2nd counter
end
No.A1961-10/14
LV8773
(7-3) Auto reset type
In the automatic reset mode, when the output current exceeds the detection current level, the output waveform
changes to the switching waveform.
As with the latch system, when the output short-circuited state is detected, the short-circuit protection circuit is
activated. When the operation of the short-circuit detection circuit exceeds the timer latch time (Tcem) described later,
the output is changed over to the standby mode and is reset to the ON mode again in 2ms (typ). In this event, if the
overcurrent mode still continues, the switching mode described above is repeated until the overcurrent mode is
canceled.
(7-4) Unusual condition warning output pins (EMO1, EMO2)
The LV8773 is provided with the EMO pin which notifies the CPU of an unusual condition if the protection circuit
operates by detecting an unusual condition of the IC. This pin is of the open-drain output type and when an unusual
condition is detected, the EMO output is placed in the ON (EMO = Low) state.
The EMO1 pin and the EMO2 pin output unusual condition on 2ch side/ 1ch side respectively.
Furthermore, the EMO (EMO2) pin is placed in the ON state when one of the following conditions occurs.
1. Shorting-to-power, shorting-to-ground, or shorting-to-load occurs at the output pin and the output short-circuit
protection circuit is activated.
2. The IC junction temperature rises and the thermal protection circuit is activated.
Unusual condition
EMO1
EMO2
Channel 1 short-circuit detected
ON
-
Channel 2 short-circuit detected
-
ON
Overheating condition detected
ON
ON
(7-5) Timer latch time (Tcem)
The time taken for the output to be set to OFF when the output has been short-circuited can be set using capacitor
Ccem, connected between the CEM pin and GND. The value of capacitor Ccem is determined by the formula given
below.
Timer latch : Tcem
Tcem ≈ Ccem × Vtcem/Icem [sec]
Vtcem : Comparator threshold voltage, typ 1V
Icem : CEM pin charge current, typ 10μA
(8) Charge Pump Circuit
When the ST pin is set High, the charge pump circuit operates and the VG pin voltage is boosted from the VM voltage
to the VM + VREG5 voltage.
Begin the drive of the motor after the time of tONG or more because it doesn't turn on the output if the voltage of the
VG pin is not pressured to VM+4V or more.
ST
VG pin voltage
VM+VREG5
VM+4V
VM
tONG
VG Pin Voltage Schematic View
No.A1961-11/14
LV8773
Application Circuit Example
• Stepping motor driver circuit
24V
+ 1
CP2
VM 28
2
CP1
VG 27
3
VREG5
4
ATT
5
EMO1
VM1 24
6
CEM
RF1 23
7
EMM
8
CHOP
PGND 25
LV8773
100pF
OUT1A 26
OUT1B 22
OUT2A 21
200pF
M
9
Position detection
monitor
Logic input
EMO2
RF2 20
10 DC22
VM2 19
11 DC21
PGND 18
12 DC12
OUT2B 17
13 DC11
GND 16
14 ST
VREF 15
+ 1.5V
The formulae for setting the constants in the examples of the application circuits above are as follows :
Constant current (100%) setting
When VREF = 1.5V
IOUT = VREF/5/RF resistance
= 1.5V/5/0.3Ω = 1.0A
Chopping frequency setting
Fchop = Ichop/ (Cchop × Vtchop × 2)
= 10μA/ (220pF × 0.5V × 2) = 45.4kHz
Timer latch time when the output is short-circuited
Tcem = Ccem × Vtcem/Icem
= 100pF × 1V/10μA = 10μs
No.A1961-12/14
LV8773
• DC motor driver circuit (Constant current control function is used.)
24V
+ -
Channel 1 short-circuit
state detection monitor
1
CP2
VM 28
2
CP1
VG 27
3
VREG5
4
ATT
5
EMO1
VM1 24
6
CEM
RF1 23
7
EMM
8
CHOP
9
EMO2
PGND 25
LV8773
100pF
OUT1A 26
M
OUT1B 22
OUT2A 21
200pF
Channel 2 short-circuit
state detection monitor
Logic input
RF2 20
10 DC22
VM2 19
11 DC21
PGND 18
12 DC12
OUT2B 17
13 DC11
GND 16
14 ST
VREF 15
M
+ 1.5V
The formulae for setting the constants in the examples of the application circuits above are as follows :
Constant current limit (100%) setting
When VREF = 1.5V
Ilimit = VREF/5/RF resistance
= 1.5V/5/0.3Ω = 1.0A
Chopping frequency setting
Fchop = Ichop/ (Cchop × Vtchop × 2)
= 10μA/ (220pF × 0.5V × 2) = 45.4kHz
Timer latch time when the output is short-circuited
Tcem = Ccem × Vtcem/Icem
= 100pF × 1V/10μA = 10μs
No.A1961-13/14
LV8773
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PS No.A1961-14/14
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