FREESCALE MC34920FNR2

Freescale Semiconductor
Advance Information
Document Number: MC34920
Rev. 2.0, 1/2007
2.8 Ω (Typ) Quad H-Bridge
Motor Driver
34920
The 34920 is a multifunctional analog ASIC. The 34920 integrates
two circuits, four H-bridge drivers, a reset circuit in a single IC, and
two DC/DC switching voltage regulators. Input voltage is 21 V to 42
V DC.
H-BRIDGE MOTOR DRIVERS
Each motor of the two driver blocks can be configured as either a
DC motor driver with pulse width modulation (PWM)-control or a
single bipolar step motor driver. In step motor mode, both drivers are
capable of being operated in the quarter step mode.
In DC motor mode, both bridges in a driver are in parallel, providing
2.4 A of drive current. In step motor mode, each bridge in a driver
drives one phase. Each phase is driven with a bipolar current mode
drive.
Features
• Individual Thermal Limit Protection
• User-Selectable Motors: 2 DC Motors (2.4 A / Motor), 2 Step
Motors (W1-2 Phase Control), 1 DC Motor and 1 Step Motor
• 2 Buck Regulators (Switching @ 200 kHz)
• VV2 Output Voltage Is Programmable to 10 V to 15 V DC
(Externally Set)
• Low-Voltage Detection Reset (VV1 and VVB+)
FN SUFFIX
EI SUFFIX (PB-FREE)
98ASB42598B
44-PIN PLCC
ORDERING INFORMATION
Device
MC34920FN/R2
MC34920EI/R2
Temperature
Range (TA)
Package
-40°C to 125°C
44 PLCC
• Pb-Free Packaging Designated by Suffix Code EI
VVB+
VV1
VV2
+
+
V2_FB
VB+
V2_SWITCH
SDI
V1_SWITCH
MCU
RESET
V1_FB
34920
DR1A
DC
MOTOR
SCLK
DR2A
CS
DR1B
DR1PWM
DR2PWM
GND
DC
MOTOR
CP1
CP2
DR2B
VB
VVB+
+
Figure 1. 34920 Simplified Application Diagram
* This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
© Freescale Semiconductor, Inc., 2007. All rights reserved.
BLOCK DIAGRAM
V1
Regulator
Oscillator
V2
Regulator
VB+
VB
CP2
CP1
V2_FB
V2_SWITCH
V1_FB
V1_SWITCH
VB+
BLOCK DIAGRAM
Boost
Voltage
Generator
DR1A1
DR1B1
DR1SENSE1
RESET
DR1A2
DR1B2
RESET
CS
SCLK
SDI
DR1PWM
DR2PWM
Serial
Input
Port
Control Logic-PWM Drive
DR1SENSE2
DR2A1
DR2B1
DR2SENSE1
DR2A2
DR2B2
DR2SENSE2
Figure 2. 34920 Simplified Internal Block Diagram
34920
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Analog Integrated Circuit Device Data
Freescale Semiconductor
PIN CONNECTIONS
GND
DR1A2
DR1SENSE2
DR1B2
DR2PWM
VB+
DR1PWM
DR1B1
DR1SENSE1
DR1A1
GND
28
27
26
25
24
23
22
21
20
19
18
PIN CONNECTIONS
V1_SWITCH
DR2_MODE
37
9
DR1_MODE
V2_FB
38
8
V1_FB
GND
39
7
GND
6
10
GND
36
5
VB+
V2_SWITCH
VCC
11
4
35
RESET
DR2A1
VB+
3
12
CP1
34
2
DR2SENSE1
DR2A2
CP2
13
1
33
VB
DR2B1
DR2SENSE2
44
14
AGND
32
43
VB+
DR2B2
CS
15
42
31
SCLK
VB+
VB+
41
GND
16
40
17
30
SDI
29
VB+
GND
GND
Figure 3. 34920 Pin Connections
Table 1. 34920 Pin Definitions
Pin Number
Pin Name
Formal Name
Definition
1
VB
Output pin to VVb
Pin to connect to VVb capacitor.
2
CP2
Capacitor to CP1
Pin for boost generator switch capacitor.
3
CP1
Capacitor to CP2
Pin for boost generator switch capacitor.
4
RESET
Reset Output
5
VCC
VCC Supply Voltage
6, 7, 17, 18,
28, 29, 39, 40
GND
Substrate Ground
8
V1_FB
V1 Regulator Feedback Input
9
DR1_MODE
Mode Select for Driver 1
10
V1_SWITCH Internal MOSFET Source for V1
Regulator
Active low Reset output.
VCC power input for internal use. The 34920 accepts either 3.3 V ±10% or
5.0 V ±5% for its logic voltage.
Ground connections for digital IC circuitry.
Voltage feedback for the V1 regulator.
Selects operational mode of Driver 1; Step = 1 / DC = 0.
Switching output for V1 regulator.
11, 15, 16,
23, 30, 31, 35
VB+
VB+ (Bulk) Supply Voltage
High-voltage supply for motors and regulators.
12
DR2A1
Driver 2, Bridge 1, Output A
Motor driver output.
13
DR2SENSE1
Driver 2, Bridge 1, I Sense
Current sense for current mode.
14
DR2B1
Driver 2, Bridge 1, Output B
Motor driver output.
19
DR1A1
Driver 1, Bridge 1, Output A
Motor driver output.
20
DR1SENSE1
Driver 1, Bridge 1, I Sense
Current sense for current mode.
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
3
PIN CONNECTIONS
Table 1. 34920 Pin Definitions (continued)
Pin Number
Pin Name
Formal Name
Definition
21
DR1B1
Driver 1, Bridge 1, Output B
22
DR1PWM
Driver 1 PWM Input
PWM input for Driver 1. Used only when DR1_MODE pin = 0.
24
DR2PWM
Driver 2 PWM Input
PWM input for Driver 2. Used only when DR2_MODE pin = 0.
25
DR1B2
Driver 1, Bridge 2, Output B
Motor driver output.
26
DR1SENSE2
Driver 1, Bridge 2, I Sense
Current sense for current mode.
27
DR1A2
Driver 1, Bridge 2, Output A
Motor driver output.
32
DR2B2
Driver 2, Bridge 2, Output B
Motor driver output.
33
DR2SENSE2
Driver 2, Bridge 2, I Sense
Current sense for current mode.
34
DR2A2
Driver 2, Bridge 2, Output A
Motor driver output.
Motor driver output.
36
V2_SWITCH Internal MOSFET Source for V2
Regulator
Switching output for V2 regulator.
37
DR2_MODE
Mode Select for Driver 2
Selects operational mode of Driver 2. Step = 1 / DC = 0.
38
V2_FB
V2 Regulator Feedback Input
41
SDI
Serial Port Data Input
Serial input register serial data input.
42
SCLK
Serial Data Port Clock
Serial input register clock.
43
CS
Serial Data Port Chip Select
44
AGND
Analog Ground
Switch output for V2 regulator.
Serial input register chip select input. Active low.
Ground connection for analog circuitry.
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Analog Integrated Circuit Device Data
Freescale Semiconductor
ELECTRICAL CHARACTERISTICS
MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
MAXIMUM RATINGS
Table 2. Maximum Ratings
All voltages are with respect to ground unless otherwise noted. Exceeding these ratings may cause a malfunction or
permanent damage to the device.
Ratings
Symbol
Value
Unit
VVB+
45
V
VCC(MAX)
7.0
V
IOUT
1.5
A
VMAXRST
VCC - 0.5
V
ELECTRICAL RATINGS
VB+ Supply Voltage
VCC Voltage
Bridge Output Current
Maximum Voltage on RESET
ESD Voltage
(1)
(2)
V
Human Body Model
VESD1
±1000
Machine Model
VESD2
±100
TSTG
-40 to 175
°C
Operating Ambient Temperature
TA
0 to 70
°C
Operating Junction Temperature
TJ
135
°C
PD
2.0
W
TSOLDER
220
°C
RθJA
37
°C/W
THERMAL RATINGS
Storage Temperature
Power Dissipation (TA = 25° C)
Pin Soldering Temperature
(3)
(4)
Thermal Resistance, Junction to Ambient
(5)
Notes
1. RESET is an open drain (open collector) output with an internal pull-up resistor.
2. ESD testing is performed in accordance with the Human Body Model (HBM) (CZAP = 100 pF, RZAP = 1500 Ω), the Machine Model (MM)
(CZAP = 200 pF, RZAP = 0 Ω), and the Charge Device Model (CDM), Robotic (CZAP = 4.0pF).
3.
4.
5.
Maximum power dissipation at indicated ambient temperature in free air with no heatsink used.
Pin soldering temperature limit is for 10 seconds maximum duration. Not designed for immersion soldering. Exceeding these limits may
cause malfunction or permanent damage to the device.
RθJA is dependent on customer application and PCB layout.
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
5
ELECTRICAL CHARACTERISTICS
STATIC ELECTRICAL CHARACTERISTICS
STATIC ELECTRICAL CHARACTERISTICS
Table 3. Static Electrical Characteristics
Characteristics noted under conditions 21 V ≤ VVB+ ≤ 42 V, TA = 10°C to 55°C, TJ max = 135°C, VCC = 5.25 V max unless
otherwise noted. Typical values noted reflect the approximate parameter mean at TA = 25°C under typical conditions unless
otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
VVB+ Supply Voltage
VVB+
21
–
42
V
VVB+ Standby Current
IVB+
POWER INPUT
VVB+ = 42 V, ICC Load = 5.0 mA, No Serial Clock, No Motor Driver,
No Load on VV2
CMOS LOGIC LEVEL
mA
1.0
14
55
(6)
Input Current, High-Voltage State
IIH
–
0.1
170
µA
Input Current, Low-Voltage State
IIL
-170
-0.1
–
µA
Input Low Input Voltage State
VIL
V
VCC + 3.3 V ±10%
–
–
0.8
VCC + 5.0 V ±5%
–
–
1.5
VCC + 3.3 V ±10%
2.1
–
–
VCC + 5.0 V ±5%
3.3
–
–
-4.0%
Nom
+4.0%
Input High-Voltage State
VIH
V
V1 AND V2 VOLTAGE REGULATORS
Regulator Output Voltage
Regulator Thermal Shutdown Junction Temperature
Regulator Thermal Junction Temperature
VOUT
TJ (SHUTDOWN)
155
–
V
175
o
C
o
C
TJ (ENABLE)
135
–
155
Overcurrent Detect Level (Peak) for IV1_SWITCH
IOC_V1
1.5
2.0
2.5
A
Overcurrent Detect Level (Peak) for IV2_SWITCH
IOC_V2
2.5
3.25
4.0
A
Short Circuit Detect Level (Peak) for IV1_SWITCH
ISC_V1
0.75
1.25
1.75
1.75
2.25
2.75
In Soft Start and Foldback Modes
Short Circuit Detect Level (Peak) for IV2_SWITCH
ISC_V2
In Soft Start and Foldback Modes
V1 Switching MOSFET on Resistance
Internal Reference Value of 2.50 V ±2%
Turn-Off Regulator
VV1 Output / VV2 Output = 0 V
Ω
–
2.0
–
–
0.75
–
VV1_FB,
VV2_FB
–
2.5
–
VOFFV1_FB,
VOFFV2_FB
3.0
–
–
Ω
RDS(ON)V2
Full On, Typical Value @ TJ = 25°C
Regulator Feedback Input
A
RDS(ON)V1
Full On, Typical Value @ TJ = 25°C
V2 Switching MOSFET on Resistance
A
V
V
Notes
6. Applicable to all logic level input signals. Inputs are to be designed to accept 3.3 V logic levels and be +5.0 V tolerant.
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Analog Integrated Circuit Device Data
Freescale Semiconductor
ELECTRICAL CHARACTERISTICS
STATIC ELECTRICAL CHARACTERISTICS
Table 3. Static Electrical Characteristics (continued)
Characteristics noted under conditions 21 V ≤ VVB+ ≤ 42 V, TA = 10°C to 55°C, TJ max = 135°C, VCC = 5.25 V max unless
otherwise noted. Typical values noted reflect the approximate parameter mean at TA = 25°C under typical conditions unless
otherwise noted.
Characteristic
Voltage Overshoot
Symbol
Typ
Max
–
5.0%
–
VOVRSHT
External VCC Load Current from 0.01 to 0.500 A, tRISE > 100 ns
Load Ripple
Min
–
VOUTRIPPLE
0.5 A maximum
Unit
mV
–
100
–
10
–
14
–
–
0.6
–
–
1.6
450
550
650
300
–
440
VBOOST GENERATOR
Charge Pump Output Voltage
VVB -VVB+
ILOAD = 1.0 mA
V
BIPOLAR CURRENT REGULATED STEP MOTOR DRIVE SYSTEM
Peak Step Motor Current, Phase A or B
Motor Not Stalled
Maximum Allowable Voltage Drop Across Any H-Bridge Switch
ISTEPMOTOR
PEAK
VDROP
ILOAD = 0.6 A (from Output to GND) or ILOAD = 0.6 A (from VVB+ to
Output)
Comparator High Threshold Voltage
Step Motor Driver Thermal Enable Junction Temperature
Single MOSFET
mV
105
–
255
-1.0
0.1
1.0
TJ (SHUTDOWN)
155
–
175
oC
TJ (ENABLE)
135
–
155
o
IOOFF
VOOFF = 5.0 V
Step Motor Driver Thermal Shutdown Junction Temperature
mV
VTL
CURR_I0_PHASEX=0, CURR_I1_PHASEX=1
VOOFF Output Leakage Current for Step Motor Driver Outputs
mV
VTM
CURR_I0_PHASEX=1, CURR_I1_PHASEX=0
Comparator Low Threshold Voltage
V
VTH
CURR_I0_PHASEX=0, CURR_I1_PHASEX=0
Comparator Medium Threshold Voltage
A
mA
Ω
RDS(ON)
Typical Value @ TJ = 25°C
C
–
1.43
–
DC MOTOR DRIVE SYSTEM
Maximum Allowable Voltage Drop Across Any H-Bridge Switch
VDROP
ILOAD = 0.75 A (from Output to GND) or ILOAD = 0.75 A (from VVB+ to
Output) (Using 2 H-Bridges in Parallel)
Peak DC Motor Driver Current
Motor Not Stalled (Using 2 H-Bridges in Parallel)
DC Motor Overcurrent Threshold (7)
IDCMOTOR
PEAK CURRENT
Current Allowed to Sustain for a Minimum of 100 ms (OCT delay),
Current Ripple 100 mA (Peak-to-Peak or Less)
–
–
1.3
–
–
1.2
A
IDCMOTOROCT
Motor Stalled (Paralleled H-Bridges Used for DC Motor Drive)
DC Motor Driver Sustaining Current Value
V
A
1.6
2.0
2.5
IDC_SUSTAIN
A
1.6
2.0
2.4
Notes
7. Because the current clamp is applied to the top H-bridge transistors only, overcurrent protection applies to motor currents. But note that
no short circuit protection exists against shorts from the DC motor outputs (DR1A1, DR1A2, DR1B1, or DR1B2 to substrate ground or
to VB+.
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
7
ELECTRICAL CHARACTERISTICS
STATIC ELECTRICAL CHARACTERISTICS
Table 3. Static Electrical Characteristics (continued)
Characteristics noted under conditions 21 V ≤ VVB+ ≤ 42 V, TA = 10°C to 55°C, TJ max = 135°C, VCC = 5.25 V max unless
otherwise noted. Typical values noted reflect the approximate parameter mean at TA = 25°C under typical conditions unless
otherwise noted.
Characteristic
Symbol
Differential DC Motor Driver Output Voltage
VDCMD
VVB++ Rising Monotonically from 0 V to 42 V (1.0 µs < tR < 10 ms)
OR
VVB+ Falling Monotonically from 42 V to 0 V (1.0 µs < tF < 10 ms)
DC Motor Driver Thermal Shutdown Output Voltage
DC Motor Driver Thermal Enable Junction Temperature
Equivalent Resistance
Typ
Max
Unit
V
–
–
4.0
VOH_DCM
IOH = 0.1 V
DC Motor Driver Thermal Shutdown Junction Temperature
Min
V
VVB+ 0.5 V
–
–
TJ (SHUTDOWN)
155
–
175
oC
TJ (ENABLE)
135
–
155
o
–
0.73
–
VCC - 0.5 V
–
–
–
–
0.2
Ω
RDS(ON)
Using 2 H-Bridges in Parallel, Nom Value @ TJ = 25°C
C
RESET
RESET High-State Output Voltage
VOH
IOH = -0.1 mA
RESET Low-State Output Voltage
VOL
VV1_FB < VV1T+
Input Low Voltage State
V
V
VIL
V
VCC + 3.3 V ±10%
–
–
0.8
VCC + 5.0 V ±5%
–
–
1.5
Input High-Voltage State
VIH
V
VCC + 3.3 V ±10%
2.1
–
–
VCC + 5.0 V ±5%
3.3
–
–
1.9
2.08
2.2
2.05
2.23
2.35
13.5
15.4
16.5
RESET VV1_FB Low Threshold
VV1T-
Voltage at V1_FB
RESET VV1_FB High Threshold
VV1T+
Voltage at V1_FB
RESET VVB+ Low Threshold
VB+
V
VVB+T-
VB+
RESET VVB+ High Threshold
V
V
VVB+T+
V
13.5
16.6
20
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Analog Integrated Circuit Device Data
Freescale Semiconductor
ELECTRICAL CHARACTERISTICS
DYNAMIC ELECTRICAL CHARACTERISTICS
DYNAMIC ELECTRICAL CHARACTERISTICS
Table 4. Dynamic Electrical Characteristics
Characteristics noted under conditions 21 V ≤ VVB+ ≤ 42 V, TA = 10°C to 55°C, TJ max = 135°C, VCC = 5.25 V max unless
otherwise noted. Typical values noted reflect the approximate parameter mean at TA = 25°C under typical conditions unless
otherwise noted.
Characteristic
Symbol
Min
Typ
Max
Unit
Serial Clock Frequency
fCLK
–
4.0
12
MHz
SCLK High Width
tCLH
41.667
125
–
ns
SCLK Low Width
SERIAL INPUT PORT TIMING
tCLL
41.667
125
–
ns
Delay CS Falling to First SCLK Rising
tCS-SCLK
83.333
250
–
ns
Delay Last SCLK Rising Edge to CS Rising
tSCLK-CS
83.333
250
–
ns
Data Valid to SCLK Set-Up Time
tDSU
41.667
125
–
ns
Data Hold Time
tDHD
41.667
125
–
ns
SDI Rise Time
tRD
5.0
–
10
ns
SDI Fall Time
tFD
5.0
–
10
ns
tRFC
5.0
–
10
ns
tNCS-OFF
83.333
250
–
ns
fOP
175
200
225
kHz
V1 Duty Cycle
V1_DC
35
37.5
40
%
V2 Duty Cycle
V2_DC
80
82.5
85
%
tDEAD
15
200
350
ns
tOFF
20
29
38
µs
tBLANK
300
–
750
ns
SCLK Rise/Fall Time
CS Off-Time (tDHD + tDSU)
V1 AND V2 VOLTAGE REGULATORS
Clock Frequency Overtemperature
BIPOLAR CURRENT REGULATED STEP MOTOR DRIVE SYSTEM
Shoot-Through Delay
Off-Time
Current Blanking Time
DC MOTOR DRIVE SYSTEM
PWM Frequency
fPWM
TA = 25°C
kHz
–
20
21
Shoot-Through Delay
tDEAD
15
180
350
ns
Overcurrent Off-Time
tOC_OFF
10
40
70
µs
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
9
ELECTRICAL CHARACTERISTICS
DYNAMIC ELECTRICAL CHARACTERISTICS
Table 4. Dynamic Electrical Characteristics
Characteristics noted under conditions 21 V ≤ VVB+ ≤ 42 V, TA = 10°C to 55°C, TJ max = 135°C, VCC = 5.25 V max unless
otherwise noted. Typical values noted reflect the approximate parameter mean at TA = 25°C under typical conditions unless
otherwise noted.
Characteristic
Symbol
Min
Typ
Max
15
33
50
10
20
30
Unit
RESET
RESET Delay
tDELAY
VV1_FB ≥ VV1T+
VCC Out-of-Tolerance Persistence Time
10% to 90%
90% to 10%
tR
(8)
RESET Fall Time
(8)
µs
tPERSIST
RESET De-Asserted, VV1_FB < VV1TRESET Rise Time
ms
ns
–
630
750
–
11
50
tF
ns
Notes
8. Test circuit is 50 pF capacitor from RESET to GND.
34920
10
Analog Integrated Circuit Device Data
Freescale Semiconductor
ELECTRICAL CHARACTERISTICS
TIMING DIAGRAMS
TIMING DIAGRAMS
TcstSCLK-CS
- SCLK
tCS-SCLK
Tcs
+ SCLK
nCS
CS
Data
latched
rising
Data Latched
on theon
rising
edge edge
of SCLKof SCLK
SCLK
SCLK
tDSU
Tdsu
SDI
SDI
Bit 11
Bit
Bit 22
Bit
Bit 33
Bit
Bit 44
Bit
Bit
Bit55
tDHD
Tend
Bit 66
Bit
Bit
Bit77
Bit
Bit88
Bit 99
Bit
Bit 10
Bit
10
Bit
Bit1111
Bit
Bit1212
Bit
Bit1313*
SDI Stays at Last Value
LSB
LSB
MSB
MSB
Time
Time
*SDI stays at last value
Figure 4. Serial Connectivity Diagram
Power
On
Power On
VCC
VCC
“Glitch”
Response
“Glitch” Response
Trip Level
Trip level
V
V1T
VtVCC
Power
Off
Power Off
Trip Level
VV1T
Trip level
VtVCC
Short
Shortglitch
glitchbelow
below VV1T
forVtVCC
less than
tPERSIST
for less
than Tpersist
1.0
1 VV
RESET
n RESET
undefined
Undefined
Undefined
undefined
15-50mS
t DELAY Tdelay
15–50
ms
(plus Tpersist delay)
(plus t PERSIST)
t PERSIST
Tdelay 15–50
15-50 mS ms
t DELAY
(plus Tpersist delay_
(plus t PERSIST)
t PERSIST
Tpersist delay
Tpersist delay
Assumes VB+ > VtVB+ during the entire period
Figure 5. RESET Generation Timing Diagram (Assumes VVB+ > VVB+T+ During Entire Period)
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
11
FUNCTIONAL DESCRIPTION
INTRODUCTION
FUNCTIONAL DESCRIPTION
INTRODUCTION
The 34920 is a multifunctional analog IC that can be used
in printer and scanner applications. It integrates two
switching voltage regulator circuits, four H-bridge drivers, and
a reset circuit in a single IC. All 34920 control lines are
compatible with CMOS type 3.3 V and 5.0 V logic.
and off. However, the Enable bit does not effect the V1
voltage regulator. The Enable bit will disable the V2 voltage
regulator and disable all motor driver circuits.
SWITCHING VOLTAGE REGULATOR CIRCUITS
The two motor drivers can be selectable as either a bidirectional DC motor driver, with PWM control and peak
currents of 2.4 A, or a bipolar step motor driver, with average
current levels of 183 mA and 550 mA per phase, and quarter
step mode capability. In step mode, both drivers are capable
of being operated in the quarter step mode.
Two switching voltage regulators provide the following
voltages from an unregulated input of 21 V to 42 V DC. Both
are buck-type switching regulators using a MOSFET (internal
to the 34920), current sense resistor (internal to the 34920),
Schottky diode (external to the 34920), external inductor, and
filter capacitor.
• V1 Voltage Regulator – This regulator is programmable,
has a duty cycle of 37%, and provides either 3.3 V
(+5%/-4%) or 5.0 V (+5% / -4%) at a current of 10 mA
(minimum) to 500 mA (maximum).
• V2 Voltage Regulator – This regulator has a
programmable output voltage (by means of an external
resistor divider network) in the range of 10 V to 15 V
±2% with a VB+ supply voltage range of 21 V to 42 V.
The V2 voltage regulator is controlled by an Enable bit in
the serial register that allows software to turn this regulator on
MOTOR DRIVERS
RESET GENERATION
The 34920 provides an output, RESET, that drives an
external reset signal to the system microprocessor and / or the
system digital logic IC. This signal is an active low logic level
signal that is derived by monitoring the level of the VB+ and
V1_FB pins.
When RESET is asserted, either internally or from an
external source, all 34920 motor driver outputs will be in their
inactive states, and the serial input port will be loaded with the
reset value.
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
INPUT POWER SUPPLY (VVB+)
The input voltage for the switching regulators and motor
drivers. VVB+ has a voltage range of 21 V to 42 V.
CMOS LOGIC LEVEL
CMOS logic level specifications are described on page 6
of the Static Electrical Characteristics table.
34920 INPUT
Table 5, page 13, describes the 34920 input
specifications.
SERIAL INPUT PORT
The 34920 provides a serial input port for bit depth of 13
bits of input. This port provides an interface between the
34920 and the digital controller IC. This port is write-only. The
interface consists of three signal lines: chip select (CS, active
low), serial clock (SCLK), and serial data input (SDI).
The digital controller initiates a serial transfer by pulling
low the chip select line (CS). It then generates 13 clock pulses
on the SCLK pin while presenting the serial data on the serial
data input (SDI). The 34920 presents the data on SDI one
setup time (t DSU) before the rising edge of SCLK. The data is
held constant for the data hold time (t DHD) beyond the SCLK
rising edge. The data is shifted into the 34920 on the rising
edge of SCLK. The least significant bit (LSB) is the first to be
shifted out of the 34920 on the rising edge of SCLK, followed
by the remaining bits to the last of the 13 bits, which is the
most significant bit (MSB). The CS line is then returned to a
high state. The low-to-high transition of CS will load the data
into the internal 34920 input register, where all the inputs are
presented to their appropriate functions in a parallel fashion.
Note The minimum off-time (CS signal equal to logic [1])
for the CS signal needs to be at least 1.0 t DSU delay +
1.0 t DHD delay. This will provide the time for the 34920 to
clear the serial input data register (transfer the serial data in
parallel to internal latches that use the data) and thereby
avoid a data overrun condition and loss of data. See the serial
input port timing data in the Dynamic Electrical
Characteristics table, page 9.
34920
12
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
Table 5. 34920 Input Specifications
Name
Description
V1_FB
Voltage feedback for the V1 regulator.
VCC
VCC power input for internal use. The 34920 accepts either 3.3 V ±10% or 5.0 V ±5% for its logic voltage.
V2_FB
Voltage feedback for the V2 regulator.
CS
Serial input register chip select input. Active low.
SCLK
Serial input register clock.
SDI
Serial input register serial data input.
DRxPWM
PWM input for the DC motor driver for either Driver 1 or Driver 2.
DRx_MODE
Selects mode of each motor driver. Step = 1/ DC = 0.
The following inputs are through the Serial Input Register
V2_Enable
Enable bit to turn on and off the V2 regulator and the motor drivers. When low (= logic [0]), the V2 regulator and
the motor drivers are turned off and the 34920 is placed in its lowest possible power state. V1 is not affected
by the Enable bit.
DR1_CURR_I1_PHASEA
Second of two inputs that control the current level in the step motor Phase A winding (Driver 1 / Step Mode).
DR1_CURR-I0_PHASEA
First of two inputs that control the current level in the step motor Phase A winding (Driver 1 / Step Mode).
DR1_DIR_PH_A
Controls the direction of the current flow through Phase A of the step motor; i.e., logic [1] level causes
conventional current flow from DR1A1 to DR1B1 (Driver 1 / Step Mode).
DR1_CURR_I1_PHASEB
Second of two inputs that control the current level in the step motor Phase B winding (Driver 1 / Step Mode).
DR1_CURR_I0_PHASEB
First of two inputs that control the current level in the step motor Phase B winding (Driver 1/ Step Mode).
DR1_DIR_PH_B
Controls the direction of the current flow through Phase B of the step motor. A logic [1] level causes
conventional current flow from DR1A2 to DR1B2 (Driver 1 / Step Mode).
DR2_CURR_I1_PHASEA
Second of two inputs that control the current level in the step motor Phase A winding (Driver 2 / Step Mode).
DR2_CURR_I0_PHASEA
One of two inputs that control the current level in the step motor Phase A winding (Driver 2 / Step Mode).
DR2_DIR_PH_A
Controls the direction of the current flow through Phase A of the step motor. A logic [1] level causes
conventional current flow from DR2A1 to DR2B1 (Driver 2 / Step Mode).
DR2_CURR_I1_PHASEB
Second of two inputs that control the current level in the step motor Phase B winding (Driver 2 / Step Mode).
DR2_CURR_I0_PHASEB
One of two inputs that control the current level in the step motor Phase B winding (Driver 2 / Step Mode).
DR2_DIR_PH_B
Controls the direction of the current flow through Phase B of the step motor. A logic [1] level causes
conventional current flow from DR2A2 to DR2B2 (Driver 2 / Step Mode).
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
13
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
SERIAL INPUT PORT BIT DEFINITIONS
Tables 6 through 9 define the bit definitions as they apply to the 13 bits of input that are brought into the 34920 through the
serial input port. These signals are listed in bit order from LSB (first bit to be shifted in) to MSB (last bit to be shifted in).
Table 6. Serial Input Port Definition for Step / Step Mode
Bit
Reset
Value
V2_Enable
1
1
Enable bit to turn on and off the V2 regulator and the motor drivers and place the
34920 in the minimum power consumption state.
SDR2_CURR_I1_PHASEB
2
1
Second of two inputs that control the current level in the SDR2 step motor Phase B
winding.
SDR2_CURR_I0_PHASEB
3
1
One of two inputs that control the current level in the SDR2 step motor Phase B
winding.
SDR2_DIR_PH_B
4
0
Controls the direction of the current flow through Phase B of the SDR2 step motor.
A logic [1] level causes conventional current flow from PH_B+ (source) to PH_B(sink).
SDR2_CURR_I1_PHASEA
5
1
Second of two inputs that control the current level in the SDR2 step motor Phase A
winding.
SDR2_CURR_I0_PHASEA
6
1
One of two inputs that control the current level in the SDR2 step motor Phase A
winding.
SDR2_DIR_PH_A
7
0
Controls the direction of the current flow through Phase A of the SDR2 step motor.
A logic [1] level causes conventional current flow from PH_A+ (source) to PH_A(sink).
SDR1_CURR_I1_PHASEB
8
1
Second of two inputs that control the current level in the SDR1 step motor Phase B
winding.
SDR1_CURR_I0_PHASEB
9
1
One of two inputs that control the current level in the SDR1 step motor Phase B
winding.
SDR1_DIR_PH_B
10
0
Controls the direction of the current flow through Phase B of the SDR1 step motor.
A logic [1] level causes conventional current flow from PH_B+ (source) to PH_B(sink).
SDR1_CURR_I1_PHASEA
11
1
Second of two inputs that control the current level in the SDR1 step motor Phase A
winding.
SDR1_CURR_I0_PHASEA
12
1
One of two inputs that control the current level in the SDR1 step motor Phase A
winding.
SDR1_DIR_PH_A
13
0
Controls the direction of the current flow through Phase A of the SDR1 step motor.
A logic [1] level causes conventional current flow from PH_A+ (source) to PH_A(sink).
Name
Description
34920
14
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
Table 7. Serial Input Port Definition for DC Motor / DC Motor Mode (9)
Bit
Reset
Value
V2_Enable
1
1
Enable bit to turn on and off the V2 regulator and the motor drivers and place the
34920 in the minimum power consumption state.
Not Used
2
X
Not used in this mode.
Not Used
3
X
Not used in this mode.
Not Used
4
X
Not used in this mode.
Not Used
5
X
Not used in this mode.
Not Used
6
X
Not used in this mode.
DR2_DIR_DCM
7
0
Controls the direction of the current flow through the DC motor. A logic [1] level
causes conventional current flow from DR2A1 (source) /DR2A2 (source) to DR2B1
(sink) / DR2B2 (sink).
Not Used
8
X
Not used in this mode.
Not Used
9
X
Not used in this mode.
Not Used
10
X
Not used in this mode.
Not Used
11
X
Not used in this mode.
Not Used
12
X
Not used in this mode.
DR1_DIR_DCM
13
0
Controls the direction of the current flow through the DC motor. A logic [1] level
causes conventional current flow from DR1A1 (source) / DR1A2 (source) to DR1B1
(sink) / DR1B2 (sink).
Name
Description
Notes
9. DR1_MODE and DR2_MODE pins = logic [0] for DC motor drive for both drivers.
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
15
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
Table 8. Serial Input Port Definition for DR1 = Step / DR2 = DC Motor Mode
Bit
Reset
Value
V2_Enable
1
1
Enable bit to turn on and off the V2 regulator and the motor drivers and place the
34920 in the minimum power consumption state.
Not Used
2
X
Not used in this mode.
Not Used
3
X
Not used in this mode.
Not Used
4
X
Not used in this mode.
Not Used
5
X
Not used in this mode.
Not Used
6
X
Not used in this mode.
DR2_DIR_DCM
7
0
Controls the direction of the current flow through the DC motor. A logic [1] level
causes conventional current flow from DR2A1 (source) /DR2A2 (source) to DR2B1
(sink) / DR2B2 (sink).
SDR1_CURR_I1_PHASEB
8
1
Second of two inputs that control the current level in the SDR1DR1 step motor
Phase B winding.
SDR1_CURR_I0_PHASEB
9
1
One of two inputs that control the current level in the SDR1 step motor Phase B
winding.
SDR1_DIR_PH_B
10
1
Controls the direction of the current flow through Phase B of the SDR1 step motor.
A logic [1] level causes conventional current flow from PH_B+ (source) to PH_B(sink).
SDR1_CURR_I1_PHASEA
11
0
Second of two inputs that control the current level in the SDR1 step motor Phase A
winding.
SDR1_CURR_I0_PHASE
12
1
One of two inputs that control the current level in the SDR1 step motor Phase A
winding.
SDR1_DIR_PH_A
13
1
Controls the direction of the current flow through Phase A of the SDR1 step motor.
A logic [1] level causes conventional current flow from PH_A+ (source) to PH_A(sink).
Name
Description
34920
16
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
Table 9. Serial Input Port Definition for DR1 = DC Motor / DR2 = Step Mode
Bit
Reset
Value
V2_Enable
1
1
Enable bit to turn on and off the V2 regulator and the motor drivers and place the
34920 in the minimum power consumption state.
SDR2_CURR_I1_PHASEB
2
1
Second of two inputs that control the current level in the SDR2 step motor Phase
B winding.
SDR2_CURR_I0_PHASEB
3
1
One of two inputs that control the current level in the SDR2 step motor Phase B
winding.
SDR2_DIR_PH_B
4
0
Controls the direction of the current flow through Phase B of the SDR2 step motor.
A logic [1] level causes conventional current flow from PH_B+ (source) to PH_B+
(sink).
SDR2_CURR_I1_PHASEA
5
1
Second of two inputs that control the current level in the SDR2 step motor Phase
A winding.
SDR2_CURR_I0_PHASEA
6
1
One of two inputs that control the current level in the SDR2 step motor Phase A
winding.
SDR2_DIR_PH_A
7
0
Controls the direction of the current flow through Phase A of the SDR2 step motor.
A logic [1] level causes conventional current flow from PH_A+ (source) to PH_A(sink).
Not Used
8
X
Not used in this mode.
Not Used
9
X
Not used in this mode.
Not Used
10
X
Not used in this mode.
Not Used
11
X
Not used in this mode.
Not Used
12
X
Not used in this mode.
DR1_DIR_DCM
13
0
Controls the direction of the current flow through the DC motor. A logic [1] level
causes conventional current flow from DR1A1 (source) /DR1A2 (source) to DR1B1
(sink) / DR1B2 (sink).
Name
Description
VOLTAGE REGULATORS
The 34920 contains two switching voltage regulators (see
Figure 6). Both are buck-type voltage regulators using an
internal switching MOSFET. The V1 regulator provides either
3.3 V or 5.0 V at +5% / -4% tolerance. The V2 regulator’s
output voltage, VV2, is programmable through the use of an
external resistor divider network. The voltage tolerance on
the VV2 output is ±2% of the nominal voltage set point. The
switching frequency of the V1 and V2 regulators is
approximately 200 kHz.
The V1 and V2 regulators are designed with a dual-mode
current limit circuit. The current limit threshold is lowered
during the power-on period to allow for a softer start-up,
thereby reducing electrical stress in the external
components.
VVB+, the input voltage for the switching voltage
regulators, ranges from 21 V to 42 V. To minimize the ripple
current on VVB+, the V1 regulator and the V2 regulator switch
out of phase.
A boost voltage generator (VB generator), which acts as a
single-stage charge pump, provides gate drive voltage for the
switching regulators. It uses an external capacitor to store the
charge.
Output voltages VV1 and VV2 are set externally with a
resistor (1% tolerance) divider network. Input voltages at
V1_FB and V2_FB should be chosen to provide a feedback
voltage, for the required output regulated voltage, to equal
the internal regulator reference voltages of 2.5 V ±2%.
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
17
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
VVB+ (21 V to 42 V)
34920
VB+
V1_SWITCH
VV1
V1 Regulator
V1_FB
VB+
Oscillator
V2_SWITCH
VV2
V2 Regulator
V2_FB
ENABLE
VVB+ (21 V to 42 V)
VB
22 µF 25 V
Oscillator
Vb Generator
CP1
10 nF 50 V
CP2
Figure 6. Voltage Regulator Functions
VOLTAGE REGULATOR OUTPUT REQUIREMENTS
Table 10 provides a listing of the output voltages and currents. Both switchmode converters operate at approximately
200 kHz ±25 kHz.
Table 10. Voltage Regulator Output Requirements
Voltage Name
Minimum Voltage
Maximum Voltage
Load Range
VV1
-4.0% of Nominal
+4.0% of Nominal
10 mA Min, 500 mA Max DC
VV2 (10)
-2.0% of Nominal
+2.0% of Nominal
10 mA Min, 1.3 A Max DC (11)
Notes
10. This voltage is programmable within a range of 10 V to 15 V via external resistors. The voltage tolerance around any set point is ±2%
of the nominal.
11. Maximum peak duration is 400 ms.
The V1 and V2 regulators provide individual internal overtemperature sensing for protection. During an overtemperature event, when the device TJ is at or above TJ (SHUTDOWN) ,
the internal thermal protection circuit disables the drive
outputs by driving all outputs to the zero current state until the
device temperatures have dropped below the lower thermal
threshold temperature TJ (ENABLE), at which time the driver is
re-enabled.
The V1 and V2 voltage regulators may be shut down by
applying a voltage in the range of 3.0 V to 6.0 V to the
respective V1_FB and V2_FB pins. This will result in the
regulator output voltages to be equal to 0 V.
OVERCURRENT PROTECTION
Output voltages VV1 and VV2 are short circuit protected.
The outputs respond to an overcurrent situation by limiting
the internal switching duty cycle. This can be reset by
removing the main supply to the chip or when the short circuit
condition is removed. Refer to the respective IOC and ISC
34920
18
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
values for V1 and V2 voltage regulators on page 6 of the
Static Electrical Characteristics table.
POWER-SAVING MODE OF OPERATION
The V2 voltage regulator can be disabled via the serial
interface by setting the V2_Enable bit (bit 1 – LSB) to a value
of 0. This provides a reduction in the bias current provided by
the V1 supply.
V1 VOLTAGE REGULATOR
Implementation of the V1 switching voltage regulator is
accomplished through the use of an internal switch MOSFET,
internal MOSFET current sense resistor, external Schottky
diode, external inductor, and filter capacitor. The frequency of
operation of this regulator is controlled by the internal clock,
which is 200 kHz ±25 kHz. The duty cycle (on-time) for this
internal regulator clock is a fixed 37.5%. This regulator
switches out of phase from the V2 regulator to minimize ripple
current on VB+. The line regulation range is 21 V < VVB+ <
42 V. The load side regulation is specified on page 6 of the
Static Electrical Characteristics table.
This converter is designed so that the current limit
threshold is lowered during the power-on period to allow for a
“softer” start-up, thereby reducing electrical stress in the
external components. This limiting is required for their safe
operation.
The voltage is set externally with a resistor (1% tolerance)
divider network. The V1_FB input voltage should be chosen,
using external voltage divider resistors, so as to provide a
regulator feedback voltage, for the required output regulated
voltage, to equal the internal regulator reference voltage of
2.50 V ±2%. The V1 regulator is ideal for providing either
3.3 V or 5.0 V with a precision of +5% / -4%.
Output current sensing is implemented by sensing the
voltage across an internal sense resistor connected between
VB+ and the drain of the internal MOSFET. Current is
measured on a cycle-by-cycle basis. The purpose of this
current sense is to prevent damage to the 34920 and its
associated external components.
V2 VOLTAGE REGULATOR
The V2 switching voltage regulator is implemented as a
buck regulator with an internal switch MOSFET, internal
MOSFET current sense resistor, external Schottky diode,
external inductor, and filter capacitor. The frequency of
operation of this regulator is controlled by the internal clock,
which is 200 kHz ±25 kHz. This regulator switches out of
phase from the V1 regulator to minimize ripple current on
VB+.
This converter is designed so that the current limit
threshold is lowered during the power-on period to allow for a
“softer” start-up, thereby reducing electrical stress in the
external components. This limiting is required for their safe
operation.
The output voltage is variable with ±2% precision, with a
VVB+ supply voltage range of 21 V to 42 V. The exact voltage
will be set externally with a resistor (1% tolerance) divider
network. The V2_FB input voltage should be chosen, using
external voltage divider resistors, so as to provide a regulator
feedback voltage, for the required output regulated voltage,
to equal the internal regulator reference voltages of 2.50 V
±2%.
Output current sensing is implemented by sensing the
voltage across an internal sense resistor connected between
VB+ and the drain of the internal MOSFET. Current is
measured on a cycle-by-cycle basis. The purpose of this
current sense is to prevent any damage to the 34920 and its
associated external components.
Note There is a V2_Enable bit in the Serial
Communication Input register (bit 1). When this bit is set to
logic [1], the V2 voltage regulator is enabled. When this bit =
logic [0], the V2 voltage regulator is disabled. Refer to
Tables 5 through 9, pp. 13–17, for a description of this bit.
The V2_Enable bit will also disable the motor drivers.
VB GENERATOR
The boost voltage generator circuit is a charge pump
circuit using two external capacitors to provide the necessary
voltage to drive internal 34920 loads. This circuit is driven at
a frequency of 200 kHz ±25 kHz.
The VB generator is utilized exclusively by the 34920.
There is no provision for external loading. Also, there is no
disable feature for the VB generator.
MOTOR DRIVE SYSTEMS
The 34920 provides two motor drivers. Both drivers are
mode selectable to be either a multi-current level bidirectional driver for bipolar step motors or a bi-directional DC
motor driver with PWM control. The DR1_MODE (Mode1)
and DR2_MODE (Mode2) pins select whether the
appropriate motor driver will drive a step motor (pin = 1) or DC
motor (pin = 0). Figures 7 and 8 depict the two motor
configurations.
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
19
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
DR1PWM
DR1_MODE
34920
VB+
DR1
DR1A1
SDR1_DIR_PH A
Phase A H-Bridge
SDR1_CURR_I1 PHASEA
DR1B1
DR1SENSE1
SDR1_CURR_I0 PHASEA
Step
Motor
DR1_DIR_DCM
DR1A2
DR1B2
SDR1_DIR_PH_B
SDR1_CURR_I1_PHASEB
Phase B H-Bridge
DR1SENSE2
SDR1_CURR_I0_PHASEB
Figure 7. Simplified Step Application Diagram Showing 1 of 2 Step Drive Circuits
34920
20
Analog Integrated Circuit Device Data
Freescale Semiconductor
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
DR2PWM
DR2_MODE
34920
VB+
DR2
DR2A1
SDR2_DIR_PH A
Phase A H-Bridge
+
DR2B1
-
SDR2_CURR_I1 PHASEA
SDR2_CURR_I0 PHASEA
DC
Motor
DR2_DIR_DCM
DR2A2
Phase B H-Bridge
SDR2_DIR_PH_B
DR2B2
SDR2_CURR_I1_PHASEB
SDR2_CURR_I0_PHASEB
Figure 8. Simplified DC Application Diagram Showing 1 of 2 Motor Drive Circuits
BIPOLAR CURRENT REGULATED STEP MOTOR
DRIVE SYSTEM
The drive circuitry is powered by the VVB+ supply voltage.
For example, with external current sense resistors of 0.910 Ω
±1%, the drive circuitry provides drive for a bipolar step motor
at current levels of approximately 183 mA, 367 mA, and
550 mA. Current mode operation supports quarter stepping.
This drive enters the fast current decay mode when both
the CURR_I0_PHASEX and CURR_I1_PHASEX inputs are
set to the logic [1] level. In fast current decay mode, any
residual motor winding current is forced into the VVB+ supply
rail when going to a zero current state from a non-zero
current level. This forces the motor winding current toward
zero as quickly as possible.
For each of the two H-bridge drivers, controlled crossover
delay, a blanking period, and internal overtemperature
sensing are provided. The crossover delay is controlled to
provide sufficient time for cross-conduction suppression. At
no time will both the upper and lower output device on the
same side of the H-bridge be allowed to conduct
simultaneously. Also, following a turn-on event a blanking
period is included to prevent false turn-offs owing to the initial
turn-on current spike, which results from motor circuit
capacitance.
This drive has internal overtemperature sensing for
protection. During an overtemperature event, when the
device TJ is at or above TJ (SHUTDOWN), the internal thermal
protection circuit disables the drive outputs by driving all
outputs to the zero current state until the device temperatures
have dropped below the lower thermal threshold temperature
TJ (ENABLE), at which time the driver is re-enabled.
Note During power-on the step motor driver circuit inhibits
its outputs when VVB+ is at 4.0 V or greater until RESET is
released. Likewise, during power-down the step motor driver
circuit inhibits its outputs from the point when RESET goes
low until VVB+ has dropped below 4.0 V.
34920
Analog Integrated Circuit Device Data
Freescale Semiconductor
21
FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
DC MOTOR DRIVE SYSTEM
This drive circuitry provides bi-directional drive to a DC
motor via two inputs, DCM_PWM (an external pin, CMOScompatible input) and DRx_DIR_DCM (a bit in the serial input
port; refer to Tables 7 through 9, pp. 15–17). This drive is
powered from VB+. The DC motor control circuitry uses
voltage mode control.
To drive a DC motor the 34920 outputs DR2A1 and
DR2A2 must be connected together externally, then
connected to the DC motor “+” lead. Likewise, the 34920
outputs DR2B1 and DR2B2 must be connected together
externally, then connected to the DC motor “-“ lead (see
Figure 8).
This drive provides internal overtemperature sensing for
protection. During an overtemperature event, when the
device TJ is at or above TJ (SHUTDOWN), the internal thermal
protection circuit disables the drive outputs by driving both
outputs to the high state until the device temperatures have
dropped below the lower thermal threshold temperature
TJ (ENABLE), at which time the drive is re-enabled.
The crossover delay must be controlled to provide
sufficient time for cross-condition suppression. At no time can
both the upper and lower output devices on the same side of
the H-bridge be allowed to conduct simultaneously. Also,
following a turn-on event a blanking period is included to
prevent false turn-offs owing to the initial turn-on current
spike, which results from motor circuit capacitance.
Note During power-on the DC Motor Driver circuit inhibits
its outputs when VVB+ is at 4.0 V or greater until RESET is
released. Likewise, during power-down of the machine the
DC Motor Driver circuit inhibits its outputs from the point
when RESET goes low until VVB+ has dropped below 4.0 V.
RESET FUNCTIONALITY
The 34920 provides an output, RESET, that drives an
external reset signal to the system microprocessor and/or the
system digital logic IC. This signal is an active low logic level
signal that is derived by monitoring the level of the VCC pin.
This output is the equivalent of an open drain- (or open
collector-) type output, with an internal 2.5 kΩ pull-up to VCC.
This output pin can be driven by other external sources and
therefore the state of RESET must be monitored by the
34920.
Note When RESET is asserted either internally or from an
external source, all 34920 motor drive outputs will be in their
inactive states, and the serial input port will be loaded with the
“Reset Value” (refer to Tables 6 through 9). The V2 voltage
regulator will be enabled.
During power-up this output asserts a logic low level, and
it monitors the V1 regulator output voltage and detects the
point that it reaches VV1T+ . The output will then remain low
for a delay of 15 ms to 50 ms before releasing to a high state.
A second case is if VV1_FB is at or above VV1T+ for a period
longer than the delay period of tDELAY and VVB+ is still less
than VVB+T- . In this situation RESET will remain low until VVB+
is greater than VVB+T- , at which point RESET will be released
immediately and there will be no delay period. If VVB+ passes
through VVB+T+ during the tDELAY period, RESET will remain
low until the end of the tDELAY period, which started at the time
VV1_FB passed through the VV1T+ level.
During power-down this output immediately asserts a logic
low at the point when VV1_FB drops down to the trip point of
VV1T- . Also, if VVB+ drops below VVB+T- and VV1_FB is still at
or above VV1T- , RESET will be pulled low.
RESET BEHAVIOR
The following conditions describe the behavior of the
RESET circuit.
A Note on Terminology Assertion of RESET is defined
as the RESET pin outputting a logic low voltage, and deassertion is when the pin is pulled up to the VCC voltage.
On the power-up condition, RESET behaves as follows:
• If 1.0 V < VV1_FB < VV1T+ or VVB+ < VVB+T+ , RESET will
be asserted.
Important If VV1_FB < 1.0 V, RESET is undefined.
• If RESET is asserted owing to VV1_FB < VV1T- , then
when VV1_FB rises monotonically from below VV1T- to
above VV1T+ , RESET will de-assert after a duration of
tDELAY.
• If RESET is asserted owing to VVB+ < VVB+T+ and
VV1_FB ≥ VV1T+ , then when VVB+ rises to the VVB+T+
level RESET will de-assert with no delay. The only case
where a delay would be seen is if the time period from
where VV1_FB rises to the VV1T+ level to the point where
VVB+ rises to the VVB+T+ level is less than the tDELAY
period. Then the delay in de-asserting RESET would be
the remaining tDELAY time, thereby maintaining the full
tDELAY period, between the time when VV1_FB reaches
VV1T+ and the de-assertion of RESET, that is required
for a reliable system reset.
On the power-down condition, RESET behaves as follows:
• If RESET is not asserted, and the VV1_FB voltage
monotonically decreases to a value below the negativegoing threshold of VV1T- and remains below VV1T- for
longer than tPERSIST (10 µs to 30 µs), RESET will be
asserted. RESET will remain asserted while 1.0 V <
VV1_FB < VV1T+ . If VV1_FB falls below 1.0 V, the RESET
signal is undefined.
• RESET will also be asserted when VVB+ decreases
below the VVB+T+ level. This will occur even if the
VV1_FB level is still above VV1T- .
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FUNCTIONAL DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
On the VV1_FB glitch condition, RESET behaves as follows:
• If the VV1_FB supply falls below VV1T- and remains there
for less than tPERSIST (10 µs to 30 µs), RESET will not be
asserted. However, if the condition lasts longer than
tPERSIST, RESET will be asserted for a duration of
tDELAY. The 10 µs-to-30 µs persistence time specified in
tPERSIST is for ESD rejection. The reset trigger will be a
retriggerable one-shot, where the delay pulse will be
10 µs to 30 µs for the delay timeout.
ENVIRONMENTAL SPECIFICATIONS
AMBIENT TEMPERATURE AND RELATIVE
HUMIDITY
ESD IMMUNITY
Refer to the Maximum Ratings table, page 5.
OVERTEMPERATURE PROTECTION
The 34920 implements overtemperature detection and
shutdown functions. The overtemperature circuitry monitors
the device’s internal temperature and activates thermal
shutdown circuitry when the temperature exceeds
TJ (SHUTDOWN) (155°C minimum, 175°C maximum). The
thermal shutdown condition is maintained until the die
temperature falls below TJ (ENABLE) (135°C minimum, 155°C
maximum). Each voltage regulator and motor driver circuit
has its own individual shutdown circuit.
Table 11 lists the temperature and relative humidity for
operating and storage conditions for the 34920.
Table 11. Ambient Temperature and Humidity
Condition
Temperature (°C)
% Relative Humidity
Operating
0 to 70
8.0 to 80
Storage
-40 to 150
5.0 to 80
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FUNCTIONAL DEVICE OPERATION
LOGIC COMMANDS AND REGISTERS
FUNCTIONAL DEVICE OPERATION
LOGIC COMMANDS AND REGISTERS
Table 12. Step Motor Truth Table
DIR_PH_A
CURR_I0_
PHASEA
CURR_I1_
PHASEA
IPH_A (mA)
DIR_PH_B
CURR_I0_
PHASEB
CURR_I1_
PHASEB
IPH_B (mA)
0
0
0
550
0
0
0
550
0
1
0
367
0
1
0
367
0
0
1
183
0
0
1
183
X
1
1
Off
X
1
1
Off
1
0
0
-550
1
0
0
-550
1
1
0
-367
1
1
0
-367
1
0
1
-183
1
0
1
-183
Table 13. DC Motor Drive System Truth Table
DRx_DIR_DCM
DRxPWM
High-Side A
Low-Side A
High-Side B
Low-Side B
0
0
On
Off
On
Off
0
1
Off
On
On
Off
1
0
On
Off
On
Off
1
1
On
Off
Off
On
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TYPICAL APPLICATIONS
TYPICAL APPLICATIONS
LOGIC VOLTAGE (VCC) AND RESET
INTEROPERABILITY
The 3.3 V or 5.0 V VV1 output voltage should feed back to
the VCC input pin directly (see Figure 9) to ensure that the
34920 can be properly reset during a power-down situation.
If this typology is not the one implemented, the user needs to
be aware that the VCC pin is not monitored for undervoltage.
Only the V1_FB and VB+ pins are monitored for
undervoltage. Thus, it is possible for VCC to be under voltage
without the 34920 issuing a reset.
VVB+ (21 V to 42 V)
34920
VB+
VCC
V1_SWITCH
VV1
V1 Regulator
V1_FB
VB+
Oscillator
V2_SWITCH
VV2
V2 Regulator
V2_FB
ENABLE
VVB+ (21 V to 42 V)
VB
22 µF 25 V
Oscillator
Vb Generator
CP1
CP2
10 nF 50 V
Figure 9. Voltage Regulator Functions
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25
PACKAGING
PACKAGE DIMENSIONS
PACKAGING
PACKAGE DIMENSIONS
For the most current package revision, visit www.freescale.com and perform a keyword search using the “98A” listed below.
FN SUFFIX
EI-PIN
PLASTIC PACKAGE
98ASB42598B
ISSUE E
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PACKAGING
PACKAGE DIMENSIONS
FN SUFFIX
EI-PIN
PLASTIC PACKAGE
98ASB42598B
ISSUE E
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Freescale Semiconductor
27
REVISION HISTORY
REVISION HISTORY
REVISION
2.0
DATE
8/2006
DESCRIPTION OF CHANGES
•
•
•
Implemented Revision History page
Converted to Freescale format and updated to the prevailing form and style
Added EI Pb-FREE suffix
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MC34920
Rev. 2.0
1/2007
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