Micro Linear ML4435CP Sensorless bldc motor controller Datasheet

PRELIMINARY
ML4435 Sensorless BLDC Motor Controller
GENERAL DESCRIPTION
The ML4435 provides all the circuitry for sensorless
speed control of 3 phase Brushless DC Motors. Controller
functions include start-up circuitry, Back EMF commutation control, Pulse Width Modulation (PWM) speed control, pulse-by-pulse current limiting, motor coasting, and
under-voltage protection.
Motor starting is accomplished by commutating the motor
at a low frequency to produce low speed motion. The
low speed motion is used to generate a Back EMF signal.
A back EMF sampling circuit locks on to the motors position and controls commutation timing by forming a phase
locked loop (PLL). The commutation control circuitry also
outputs a speed feedback signal used in the speed control
loop. The speed control loop consists of an error amplifier
and PWM comparator that produces a PWM duty cycle
for speed regulation. Motor current is limited by a pulseby-pulse PWM shutdown comparator that is tripped by
the voltage across an external current sense resistor. Commutation control, PWM speed control, and current limiting are combined to produce the output driver signals.
Six output drivers are used to provide gating signals to an
external 3 phase bridge power stage sized for the Brushless DC (BLDC) motor voltage and current requirements.
Additional functions include a motor coast function and
an under voltage lock out circuit to shut down the output
drivers in the event of a low voltage condition on the VCC
to the ML4435.
FEATURES
n Proprietary back-EMF sensing commutation technique
for motor communication without hall effect sensors
n PWM pulse-by-pulse current limiting to protect motor
and FET drivers
n Stand-alone operation; motor starts and stops with
power applied to the IC*
n Soft-start function limits start-up current
n PWM speed control for efficiency and minimum FET
sizing
n Onboard under voltage lock out and power fail detect
n Tach output senses commutation of the motor
* Some External Components Required.
PRELIMINARY DATASHEET
May, 2000
PRELIMINARY
ML4435
WARRANTY
Micro Linear makes no representations or warranties with respect to the accuracy, utility, or completeness of the contents of
this publication and reserves the right to make changes to specifications and product descriptions at any time without notice.
No license, express or implied, by estoppel or otherwise, to any patents or other intellectual property rights is granted by this
document. The circuits contained in this document are offered as possible applications only. Particular uses or applications
may invalidate some of the specifications and/or product descriptions contained herein. The customer is urged to perform
its own engineering review before deciding on a particular application. Micro Linear assumes no liability whatsoever,
and disclaims any express or implied warranty, relating to sale and/or use of Micro Linear products including liability
or warranties relating to merchantability, fi tness for a particular purpose, or infringement of any intellectual property
right. Micro Linear products are not designed for use in medical, life saving, or life sustaining applications.
© Micro Linear 2000.
is a registered trademark of Micro Linear Corporation. All other trademarks are
the property of their respective owners.
Products described herein may be covered by one or more of the following U.S. patents: 4,897,611; 4,964,026; 5,027,116;
5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470; 5,565,761; 5,592,128; 5,594,376;
5,652,479; 5,661,427; 5,663,874; 5,672,959; 5,689,167; 5,714,897; 5,717,798; 5,742,151; 5,747,977; 5,754,012;
5,757,174; 5,767,653; 5,777,514; 5,793,168; 5,798,635; 5,804,950; 5,808,455; 5,811,999; 5,818,207; 5,818,669; 5,825,165;
5,825,223; 5,838,723; 5.844,378; 5,844,941. Japan: 2,598,946; 2,619,299; 2,704,176; 2,821,714. Other patents are pending.
2
PRELIMINARY DATASHEET
May, 2000
PRELIMINARY
ML4435
BLOCK DIAGRAM
FB A
14
NEUTRAL
SIMULATOR
18 SPEED FB
5.8kΩ
FB B
15
+
+
SIGN
CHANGER
+
LEVEL
SHIFT
– 0.7V
–
MUX
2.9kΩ
–
2 TACH
BACK
EMF SAMPLER
FB C 16
COMMUTATION
STATE MACHINE
20 CVCO
VOLTAGE
CONTROLLED
OSCILLATOR
SPEED FB
6
R
3µs
POWER ON
RESET PULSE
COMP
0.97V
4 RVCO
+
A
F
COMP
B
E
1.5V
–
8.2 + 0.7V
0.9V
+
D
SPEED SET 5
COAST
SPEED
ERROR AMP
C
–
7 HA
–
+
LEVEL SHIFT
0.7V
PWM
COMPARATOR
SPEED COMP 3
8 HB
GATING
LOGIC
AND
OUTPUT
DRIVERS
+
9 HC
11 LA
–
2.2 + 0.7V
12 LB
5V
TRIANGLE WAVE
GENERATOR
13 LC
D
Q
PULSE-BY-PULSE
CURRENT LIMIT
R
8.7V
ISENSE 1
+
–
1V
UVLO COMPARATOR
+
225kΩ
SOFT START 19
225kΩ
COMP
–
6V REFERENCE
CURRENT LIMIT
COMPARATOR
VREF
VREF + 0.7V
6
10
RT
17
VCC
GND
ML4435 Block Diagram
May, 2000
PRELIMINARY DATASHEET
3
PRELIMINARY
ML4435
PIN CONFIGURATION
ML4435
20-P n PDIP P20
20-P n SOIC S20
20
ISENSE
TACH
SPEED COMP
RVCO
SPEED SET
RT
2
3
SOFT START
ND
5
6
FB C
6
5
FB B
4
FB A
3
LC
2
LB
HB
VCC
CVCO
SPEED FB
4
HA
HC
9
9
0
LA
TOP VIEW
PIN DESCRIPTIONS
4
PIN
NAME
FUNCTION
1
ISENSE
Motor current sense input which triggers pulse by pulse current limit when
ISENSE exceeds 0.55V
2
TACH
A clock output of 6 pulses per commutation cycle when SPEED FB is greater
than 0.97V otherwise the TACH output is at 5V
3
SPEED COMP
Connection node for speed loop compensation components
4
RVCO
Connection node for external resistor to set VCO frequency
5
SPEED SET
6
RT
External resistor from this pin to ground controls the IC's PWM timing (frequency)
7
HA
High-side output driver for motor phase A
8
HB
High-side output driver for motor phase B
9
HC
High-side output driver for motor phase C
10
VCC
11
LA
Low-side output driver signal for motor phase A
12
LB
Low-side output driver signal for motor phase B
13
LB
Low-side output driver signal for motor phase C
14
FB A
Back EMF signal input for motor phase A
15
FB B
Back EMF signal input for motor phase B
16
FB C
Back EMF signal input for motor phase C
17
GND
Signal and power ground
18
SPEED FB
19
SOFT START
Connection node for external soft start capacitor which reduces start up current
20
CVCO
Connection node for external capacitor to set VCO frequency. Forcing this input
below 1.5V causes the commutation to stop and the motor to coast
DC input for setting motor speed
Power Supply input
Connection node for back-EMF sensing compensation components
PRELIMINARY DATASHEET
May, 2000
PRELIMINARY
ML4435
FUNCTIONAL DESCRIPTION
COMPONENT SELECTION
OUTPUT DRIVERS
Selecting external components for the ML4435 requires
calculations based on the motor’s electrical and mechanical parameters. The following is a list of the motor parameters needed to for these calculations:
The output drivers LA, LB, LC, HA, HB, and HC provide
totem pole output drive signals for a 3 phase bridge power
stage. All control functions in the ML4435 translate to
outputs at these pins. LA, LB, LC provide the low side drive
signals for phases A, B, and C of the 3 phase power stage
and are 12V active high signals. HA, HB, and HC provide
the high side signals for phases A, B, and C of the 3 phase
power stage and are 12V active low signals.
The maximum DC motor supply voltage V MOTOR (V)
The maximum operating current I MAX (A)
The winding resistance measured line to line Rl-l Ω
CURRENT LIMITING IN THE 3 PHASE BRIDGE
POWER STAGE
The number of magnetic poles N (Unitless)
The Back EMF constant Ke (V s/RAD)
The torque constant Kτ (N m/A) of the motor (Kτ = Ke
in SI units)
The maximum speed of operation RPMMAX (RPM)
The moment of inertia J (Kg m2 ) of the motor and its
load
The viscous damping factor ζ (Unitless) of the motor and
its load
If one or more of the above values is not known, it is
still possible to pick components for the ML4435, but
some experimentation may be necessary to determine the
optimal values. All quantities are in SI units unless otherwise specified. The following formulas and component
selection graphs should be considered as a starting point
from which to optimize the application. All calculations
for capacitors and resistors should be used as the first
approximation for selecting the closest standard value.
A current sense resistor RSENSE shown in Figure 1 is
installed in the 3 phase power stage to regulate the maximum current in the power stage and the BLDC motor.
Current regulation is accomplished by shutting off the
output drivers LA, LB, and LC for the remainder of the
PWM period if the voltage across RSENSE exceeds the
current limit threshold set by the SOFT START (pin 19).
The maximum power dissipated in RSENSE is shown in
Figure 2.
R
ISENSE
RSENSE
C
SUPPLY VOLTAGE AND ON-CHIP VOLTAGE
REFERENCE
VCC
Figure 1. Current Limit with RSENSE
The supply voltage at VCC (pin 10) is nominally
12V ± 10%. A bypass capacitor of 0.1µF to ground as
close as possible to VCC (pin 10) is recommended.
6
RT
RSENSE Po er Rat n W
5
An internal 6V reference is generated inside the ML4435.
The reference appears on RT (pin 6). A resistor to ground
on RT sets the PWM frequency. This resistor can be
replace with a potentiomenter for use in setting the speed
command. This topic is discussed under the PWM SPEED
CONTROL section. Note: Buffer this pin with an op amp
with at least a 1MΩ input impedance if external circuits
are necessary.
4
3
2
0
0
2
4
6
0
IMAX [MOTOR] A
Figure 2. RSENSE Power vs. Motor Current
May, 2000
PRELIMINARY DATASHEET
5
PRELIMINARY
ML4435
FUNCTIONAL DESCRIPTION
SOFT START
RSENSE
The voltage at SOFT START (pin 19) sets the current limit
threshold. The ML4435 has an internal voltage divider
with a 1.1V supply voltage. This circuit is shown in Figure
3. The divider consists of two 225k Ω resistors setting
the current limit threshold to approximately 0.55V. An
external voltage divider off of VCC or an external reference
can be used to override the default setting of SOFT START
by using a divider with 10 times the current draw of the
internal divider.
The function of RSENSE is to provide a voltage proportional to the motor current, for current limiting. The default
trip voltage across RSENSE is 0.6V as set by the SOFT
START (pin 19). The current sense resistor should be a
low inductance resistor such as a carbon composition. For
resistors in the milli ohms range wire wound resistors tend
to have low values of inductance. RSENSE can be selected
using Figure 4. The power rating of RSENSE should be
sized to handle the power dissipation (I MAX squared
times RSENSE) seen at maximum current.
ISENSE FILTER
. V
225kΩ
SOFT START
9
0.5V
An RC lowpass filter is required at the ISENSE input pin
to remove the voltage spike on the leading edge of the
current sense signal caused by the diode reverse recovery
shoot through current. Absent the filter, false triggering of
the current limit could occur.
225kΩ
CSOFT START
The recommended starting values for this circuit are
R = 1KΩ and C = 1000pF a configuration that will filter
out spikes less than 1µs long. It is recommended that the
capacitor value not be increased beyond 330pF.
Pulse-By-Pulse Current Limiting
Figure 3. SOFT START Function
A capacitor to ground on the SOFT START pin can be used
to provide a soft ramping of the current limit on power up.
The ramp time can be selected using Figure 4.
When current limit is activated by the voltage on ISENSE
exceeding the voltage on SOFT START the current limit is
tripped, turning off LA, LB, and LC for the remainder of
the PWM period.
COMMUTATION CONTROL
A 3 phase Brushless DC motor requires electronic com-
RAMP TIME s
30
BEFORE FILTERIN
5
0
0
50
00
C SOFT START
F
AFTER FILTERIN
Figure 4. SOFT START Ramp Time vs. CSOFTSTART
6
PRELIMINARY DATASHEET
Figure 5. ISENSE Filter Wave Forms
May, 2000
PRELIMINARY
ML4435
FUNCTIONAL DESCRIPTION
mutation to achieve rotational motion. Electronic commutation requires the switching on and off of the power
switches of a 3 phase half bridge. For torque production
to be achieved in one direction the commutation is dictated by the rotor’s position. Electronic commutation in
the ML4435 is achieved by turning on and off, in the
proper sequence, one L output from one phase and one H
output from another phase. There are six combinations of
L and H outputs (six switching states) that constitute a full
commutation cycle as illustrated in Table 1 labeled state
A through F. This switching sequence is programmed into
the commutation state machine as illustrated in Figure 6.
Clocking of the commutation state machine is provided by
the output of a VCO.
VOLTAGE CONTROLLED OSCILLATOR
The VCO outputs a TTL compatible clock on the TACH
(pin 2) proportional to the input voltage to the voltage
controlled oscillator SPEED FB (pin 18). The proportion of
frequency to voltage or VCO constant Kv is set by a resistor
to ground on RVCO (pin 4) and capacitor to ground on
CVCO (pin 20) as shown in Figure 7. RVCO sets up a
current proportional to the VCO input voltage SPEED FB
minus 0.7V. This current is used to charge and discharge
CVCO between the threshold voltages of 2V and 3.75V as
shown in Figure 7. RVCO has a lower voltage limit of 0.2V.
The resulting triangle wave of CVCO corresponds to the
clock on the TACH pin, this is also illustrated in Figure 7. Kv
should be set so that the VCO output frequency corresponds
to the maximum commutation frequency FMAX and thus the
maximum motor speed when the VCO input is equal to or
slightly less than 6V. CVCO and RVCO can be selected by
first calculating FMAX and then using the selection graph in
Figure 8. FMAX is calculated as follows:
FMAX = 0.05 x RPMMAX x N
OUTPUT DRIVERS
STATE
LA
LB
LC
HA
HB
HC
Where: RPMMAX = The maximum speed of operation
(RPM). N = The number of magnetic poles (Unitless).
A
LOW LOW HI H LOW HI H HI H
TACH
B
LOW LOW HI H HI H LOW HI H
The TACH (pin 2) outputs the VCO frequency. This is 6
C
HI H LOW LOW HI H LOW HI H
D
HI H LOW LOW HI H HI H LOW
E
LOW HI H LOW HI H HI H LOW
F
LOW HI H LOW LOW HI H HI H
SPEED FB
LEVEL
SHIFT
0. V
= DRIVER ON
+
3. 5V
Table 1. Communication Control States
VOLTA E
CONTROLLED
OSCILLATOR
COMMUTATION
STATE MACHINE
CVCO
20
2V
RVCO
4
0.9V
R
3 s
POWER ON
RESET PULSE
CLK VCO
A
F
B
E
C
D
Figure 6. Commutation State Machine
May, 2000
Figure 7. VCO Control
PRELIMINARY DATASHEET
7
PRELIMINARY
ML4435
FUNCTIONAL DESCRIPTION
times the commutation frequency. The TACH out also
indicates a low motor speed by staying TTL high when the
motor is at its minimum speed (SPEED FB below 0.97V).
BACK EMF SAMPLER
The input to the VCO (pin 18) SPEED FB is controlled by
the Back EMF Sampler. The back EMF sense pins FB A,
FB B, and FB C inputs to the back EMF sampler require
a signal from the motor phase leads that is below the
VCC of the ML4435. The phase sense input impedance is
8.7kΩ. If the motor voltage is greater than the VCC of the
ML4435 then this requires a series resistor RFB from the
motor phase lead shown in Figure 8. RFB can be selected
by using the graph in Figure 9 or using the following
equation:
RFB = 8.7kW (
VMOTOR
- 1)
12
BLDC
MOTOR
RFBA
4 FBA
RFBB
5 FBB
RFBC
6 FBC
A
B
C
Figure 8. Back EMF Sampler Configuration
The back EMF sampler takes the motor phase voltages
divided down to signals that are less than VCC (12V
nominal) and calculates the neutral point of the motor by
the following equation:
VNEUTRAL = (FB A + FB B + FB C)/3
This allows the ML4435 to compare the back EMF signal
to the motors neutral point without the need for bringing
out an extra wire on a WYE wound motor. For DELTA
wound motors there isn’t a physical neutral to bring out so
this reference point must be calculated anyway.
The back EMF sampler takes the motor phase that is not
driven (i.e. if LA and HB are on then phase A is driven
low and phase B is driven high then phase C is sampled).
The sampled phase provides a back EMF signal that is
compared against the neutral of the motor. The sampler
is controlled by the commutation state machine. The
sampled back EMF is compared to the neutral through an
error amplifier. The output of the error amplifier outputs
a charging or discharging current to SPEED FB (pin 18)
which provides the voltage to the VCO.
BACK EMF SENSING PHASE LOCKED LOOP
COMMUTATION CONTROL
The three blocks: The commutation state machine, the
VCO, and the back EMF sampler form a phase locked
loop that locks the commutation clock onto the back EMF
signal. The complete phase locked loop is illustrated in
Figure 10. The phased locked loop requires a lead lag
filter that is set by external components on SPEED FB (pin
18). The filter components in Figure 10 work for most
applications. If performance is unstable C1 and C2 can
go up or down a decade in value as low as the C2 stays
equal to C1 x 10.
2,000
FBA
4
Ω
,000
R B F A, B, C
0,000
6,000
FBB
5
BACK EMF
SAMPLER
SPEED FB
CSFB
FBC
6
VCO
4,000
COMMUTATION
STATE MACHINE
2,000
0
0
5
20
25
30
Motor Volta e [Max] V
Figure 9. RFB vs. VMOTOR [MAX]
8
PRELIMINARY DATASHEET
Figure 10. Phase Locked Loop
May, 2000
RSFB
CSFB2
RSFB2
PRELIMINARY
ML4435
FUNCTIONAL DESCRIPTION
MOTOR START-UP
When power is first applied to the ML4435, the motor is at
rest and thus, the back EMF is equal to zero. The motor
needs to be rotating for the Back EMF sampler to lock onto
the rotor position and commutate the motor. The ML4435
uses a minimum VCO frequency to begin commutating the
motor. This low frequency commutation is set by the 0.2V
clamp on RVCO, this provides a commutation frequency
at 1/30th of the maximum frequency.
The voltage on SPEED COMP (pin 3) is compared with a
triangle wave oscillator to create a PWM duty cycle. The
PWM oscillator creates a triangle wave function from 3V
to 7V as shown in Figure 11. The frequency of the triangle
wave oscillator is set by a resistor to ground on RT (pin 6).
RT can be selected from the graph in Figure 12.
The PWM duty cycle from the speed control loop is gated
the pulse-by-pulse current limit that controls the LA, LB,
and LC output drivers.
RUN MODE
After the Back EMF sensing PLL has locked on to the
motor’s position, the motor is running in closed loop control. At this point, the speed control loop should force the
motor speed to the speed that corresponds to the SPEED
SET voltage.
SPEED FB
SPEED
SET
5
PWM SPEED CONTROL
Speed control is accomplished by setting a speed command at SPEED SET (pin 5) with an input voltage from 0.2
to 6V. The accuracy of the speed command is determined
by the external components RVCO and CVCO. There are
a number of methods to control the speed command on
the ML4435. One method is to use a potentiometer from
RT to ground with the wiper going to SPEED SET. If SPEED
SET is controlled from a microcontroller, a DAC that uses
RT as its input reference can be used. The RT voltage must
be buffered connecting it to external circuits. The speed
command is compared with the sensed speed from SPEED
FB minus 0.7V (pin 18) through a transconductance error
amplifier. The output of the speed error amplifier is SPEED
COMP (pin 3). SPEED COMP is clamped between 8.2V
and 2.2V. A signal of 8.2V corresponds to full PWM duty
cycle and 2.2V corresponds to 0% duty cycle. Speed
loop compensation components are placed on this pin as
shown in Figure 11.
–
–
+
SPEED
ERROR AMP
+
LEVEL SHIFT
0. V
.2 - 0. V
SPEED
COMP
3
PWM
COMPARATOR
CSE
2.2 + 0. V
V
TRIAN LE
WAVE
COMPARATOR
+
–
3V
Figure 11. PWM Oscillator Circuit
000
C SC 2 =
Rsc =
144
. × NxKexVMOTOR × R VCO × C VCO
2 × π × J × RI × freq 2
RT kΩ
The speed loop compensation components are calculated
as follows:
00
10
2 × π × freq × Csc2
Csc1 = 10 x Csc2
0
Where freq is the speed loop bandwidth in Hz.
0
00
PWM FRE UENCY kHz
Figure 12. RT vs PWM Frequency
May, 2000
PRELIMINARY DATASHEET
9
PRELIMINARY
ML4435
FUNCTIONAL DESCRIPTION
COAST
UNDER VOLTAGE PROTECTION
When CVCO (pin 20) is pulled below 1.5V the output
drivers LA, LB, LC and HA, HB, and HC are turned off.
The COAST function shuts all power off from the motor
allowing it to coast to a stop. The COAST function in (pin
20) is configured as shown in Figure 13 and can be driven
by a switch to ground or open collector to ground also
shown in Figure 13.
Undervoltage protection is used to protect the 3 phase
bridge power stage from a low VCC condition. Undervoltage is triggered at VCC of 9.2V or under. Undervoltage
also turns off all output drivers LA, LB, LC, HA, HB, and
HC. The comparator that triggers undervoltage protection
has 500mV of hystersis.
INTERFACING THE OUTPUT DRIVERS TO THE 3
PHASE BRIDGE POWER STAGE
The most flexible configuration is to use high side drivers
to control N-Channel MOSFETs (or IGBTs) allowing applications from less than 12V up to 170V. Figure 14a shows
the ML4435 and all the support circuitry in a typical
application. Figure 14b shows a power stage using the
IR2118 high side drivers from International Rectifier and
high voltage MOSFETs.
CVCO
20
3. 5V
2V
COAST
+
COMP
–
.5V
P
Figure 13. Coast Control
N.C.
2
N.C.
3
4
5
6
9
0
TP 0 ISENSE
2
3
4
R3
k
5
6
TP 3 TACH
RUN
SW
2V
N.C.
9
N.C.
SW4PDT
TP 5 LIMIT
C3
N.C.
2200 F
N.C.
N.C.
R 0
N.C.
k
ML4435
0.33 F
ISENSE
C4
0 F
R6
TP
R4
2
20k
0k
k
R2
R
00k
20
I LIMIT
9
3
S COMP
4
RVCO
5
S SET
FB C
6
RT
FB B
SPEED SET
R
TACH
CVCO
00 F
S FB
R5
ND
HA
FB A
HB
LC
9
HC
LB
0
VCC
90.9k
TP 2
S FB
C 0
LA
5
3
2
C2
C
F
4
R
k
R9
R 2
F
PRELIMINARY DATASHEET
.0
.
k
k
May, 2000
200k
C9
C
Figure 14a. ML4435 Typical Application
10
0k
C
.033 F
4
2V
0.
R6
6
F
F
2
22
23
24
25
26
IDC 26
COAST
C5
N.C.
20
May, 2000
3
2
2
ND
LC
SC
HC
ND
LB
SB
HB
ND
LA
IDC 26
ND
ND
ND
ND
ND
2V
ND
PRELIMINARY DATASHEET
ND
LA
LB
LC
HC
25
26
HB
HA
24
23
22
2
20
9
6
ND
C 2
UNUSED
4
5
2V
ND
ND
ISENSE
F
3
2
0
9
6
5
SA 4
HA
ISENSE
P
2PIN
HV
ND
P2
R50
SA FUSE
0
C
F
390 F
200V
C 0
IR2
4
C
F
5
2N4403
2N440
F
C3
C
U2
F
5
6
0
9
.0k
3
IRF644
R3
D2 UF4005
IR2
4
3
6
0k
R35
2
IRF644
3
.0k
.5k
R32
2
F
C2
0k
R30
R3
IRF644
2
U
D UF4005
0.33 F
250V
C 3
0.33 F
250V
C 4
SA
PHASE A TERMINAL
2N4403
2N440
F
C4
0k
R36
6
IRF644
0k
R4
.5k
R3
SB
F
C5
R49
0.4 Ω
W
TERMINAL
PHASE B
IR2
4
3
2
.0k
F
C9
U3
5
6
D3 UF4005
R43
5
IRF644
2
2N4403
2N440
F
C6
0k
R42
4
IRF644
.5k
R44
SC
TERMINAL
PHASE C
0k
R4
PRELIMINARY
ML4435
FUNCTIONAL DESCRIPTION
Figure 14b. Power Stage
11
PRELIMINARY
ML4435
ELECTRICAL TABLES
Unless otherwise specified, Ta= Operating Temperature Range, VCC= 12V +/- 10%, RT= 50k
SYMBOL
PARAMETER
CONDITIONS
REFERENCE
RT
MIN
TYP
MAX
UNITS
5.8
6
6.2
V
VCO
RVCO
CVCO
Lower Range2
Upper
Range2
Lower
Threshold2
Upper Threshold2
Coast Enable Threshold2
Back EMF Blanking
SPEED FEEDBACK
Threshold2
Output Range2
V Minimum
Frequency2
TACH Out Disabled Threshold2
I Back EMF Sampler2
BACK EMF SENSING
0.2
V
6
V
2
V
3.75
V
1.5
V
2.875
V
0
6.7
V
V Speed Feedback
0.9
V
TACH Out = Hi
0.97
V
V Speed Feedback = 3.3V
+/-80
µA
Feed Back Input Range2
FB A, FB B, and FB C
TACH Out Low
ISINK = 100µA
0
VCC
V
0.4
V
TACH
TACH Out High
SPEED ERROR AMP
ISOURCE =100µA
SPEED SET Range2
0.2
4.3
4.8
0
V
6
V
I SPEED COMP
V SPEED COMP = 5.1V
+/-45
µA
SPEED COMP Output Lower Clamp2
I = ±45µA
2.15
V
SPEED COMP Output Upper Clamp2
OSCILLATOR
I = ±45µA
8.2
V
PWM Frequency
N1, N2, N3
17
Cycle2
N1, N2, N3
0
Duty
CURRENT SENSE
V SOFT START
0.48
Threshold2
0.58
33
kHz
100
%
0.68
V
0.58
ISENSE
OUTPUTS (N1, N2, N3, P1, P2, AND P3)
Output Low
25
V
ISINK = 20mA
0
0.5
1
V
ISOURCE = 20mA
0
0.5
1
V
Start Threshold
8.7
9.2
9.7
V
Under Voltage Threshold
8.2
8.7
9.2
V
Output High (VCC-VOUT)
UNDER-VOLTAGE LOCKOUT
SUPPLY
ICC
Supply Current
15
Note 1:
Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions
Note 2
Guaranteed by design, not tested
12
PRELIMINARY DATASHEET
May, 2000
mA
PRELIMINARY
ML4435
PHYSICAL DIMENSIONS (inches/millimeters)
Packa e P20
20-P n PDIP
.0 0 - .035
25.65 - 26.29
20
PIN
0.240 - 0.260 0.295 - 0.325
6.09 - 6.6
.49 - .26
ID
0.060 MIN
.52 MIN
4 PLACES
0.055 - 0.065
.40 - .65
0. 00 BSC
2.54 BSC
0.0 5 MIN
0.3 MIN
0. 0 MAX
4.32 MAX
SEATIN PLANE
0.0 6 - 0.022
0.40 - 0.56
0. 25 MIN
3. MIN
0º - 5º
0.00 - 0.0 2
0.20 - 0.3
Packa e S20
20-P n SOIC
0.49 - 0.5 2
2.65 - 3.00
20
0.29 - 0.30
.39 - .65
PIN
0.024 - 0.034
0.6 - 0. 6
4 PLACES
0.39 - 0.4 2
0. - 0.4
ID
0.050 BSC
.2 BSC
0.095 - 0. 0
2.4 - 2. 2
0º - º
0.090 - 0.094
2.2 - 2.39
0.0 2 - 0.020
0.30 - 0.5
SEATIN PLANE
May, 2000
0.005 - 0.0 3
0. 3 - 0.33
0.022 - 0.042
0.56 - .0
PRELIMINARY DATASHEET
0.00 - 0.0 5
0. - 0.3
13
PRELIMINARY
ML4435
ORDERING INFORMATION
PART NUMBER
TEMPERATURE RANGE
PACKAGE
ML4435CP
ML4435CS
0ºC to 70ºC
0ºC to 70ºC
20 Pin PDIP (P20)
20 Pin SOIC (S20)
ML4435IP
ML4435IS
-40ºC to 85ºC
-40ºC to 85ºC
20 Pin PDIP (P20)
20 Pin SOIC (S20)
Micro Linear Corporation
2092 Concourse Drive
San Jose, CA 95131
Tel: (408) 433-5200
Fax: (408) 432-0295
www.microlinear.com
DS4435-01
14
PRELIMINARY DATASHEET
May, 2000
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