MC34920EIR2 Ver la hoja de datos (PDF) - Freescale Semiconductor

Número de pieza

componentes Descripción

Fabricante

MC34920EIR2

2.8 Ω (Typ) Quad H-Bridge Motor Driver

Freescale Semiconductor 

FUNCTIONAL DESCRIPTION

FUNCTIONAL INTERNAL BLOCK DESCRIPTION

Table 9. Serial Input Port Definition for DR1 = DC Motor / DR2 = Step Mode

Name

Bit

Reset

Value

Description

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).

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%.

Analog Integrated Circuit Device Data

Freescale Semiconductor

34920

17

Share Link: